diff --git a/app/src/androidTest/java/org/thoughtcrime/securesms/messages/MessageContentProcessorTest.kt b/app/src/androidTest/java/org/thoughtcrime/securesms/messages/MessageContentProcessorTest.kt
new file mode 100644
index 0000000000..e9bd146db8
--- /dev/null
+++ b/app/src/androidTest/java/org/thoughtcrime/securesms/messages/MessageContentProcessorTest.kt
@@ -0,0 +1,31 @@
+package org.thoughtcrime.securesms.messages
+
+import android.app.Application
+import androidx.test.core.app.ApplicationProvider
+import org.junit.Rule
+import org.thoughtcrime.securesms.messages.MessageContentProcessor.ExceptionMetadata
+import org.thoughtcrime.securesms.messages.MessageContentProcessor.MessageState
+import org.thoughtcrime.securesms.testing.SignalActivityRule
+import org.whispersystems.signalservice.api.messages.SignalServiceContent
+
+abstract class MessageContentProcessorTest {
+
+  @get:Rule
+  val harness = SignalActivityRule()
+
+  protected fun MessageContentProcessor.doProcess(
+    messageState: MessageState = MessageState.DECRYPTED_OK,
+    content: SignalServiceContent,
+    exceptionMetadata: ExceptionMetadata = ExceptionMetadata("sender", 1),
+    timestamp: Long = 100L,
+    smsMessageId: Long = -1L
+  ) {
+    process(messageState, content, exceptionMetadata, timestamp, smsMessageId)
+  }
+
+  protected fun createNormalContentTestSubject(): MessageContentProcessor {
+    val context = ApplicationProvider.getApplicationContext<Application>()
+
+    return MessageContentProcessor.forNormalContent(context)
+  }
+}
diff --git a/app/src/androidTest/java/org/thoughtcrime/securesms/messages/MessageContentProcessor__handleStoryMessageTest.kt b/app/src/androidTest/java/org/thoughtcrime/securesms/messages/MessageContentProcessor__handleStoryMessageTest.kt
new file mode 100644
index 0000000000..31cedcf7a4
--- /dev/null
+++ b/app/src/androidTest/java/org/thoughtcrime/securesms/messages/MessageContentProcessor__handleStoryMessageTest.kt
@@ -0,0 +1,124 @@
+package org.thoughtcrime.securesms.messages
+
+import org.junit.After
+import org.junit.Assert.assertEquals
+import org.junit.Before
+import org.junit.Test
+import org.signal.core.util.requireLong
+import org.signal.libsignal.zkgroup.groups.GroupMasterKey
+import org.signal.storageservice.protos.groups.Member
+import org.signal.storageservice.protos.groups.local.DecryptedGroup
+import org.signal.storageservice.protos.groups.local.DecryptedMember
+import org.thoughtcrime.securesms.database.MessageDatabase
+import org.thoughtcrime.securesms.database.MmsHelper
+import org.thoughtcrime.securesms.database.SignalDatabase
+import org.thoughtcrime.securesms.database.model.MediaMmsMessageRecord
+import org.thoughtcrime.securesms.database.model.ParentStoryId
+import org.thoughtcrime.securesms.database.model.StoryType
+import org.thoughtcrime.securesms.mms.IncomingMediaMessage
+import org.thoughtcrime.securesms.recipients.Recipient
+import org.thoughtcrime.securesms.testing.TestProtos
+import org.thoughtcrime.securesms.util.FeatureFlagsTestUtil
+import org.whispersystems.signalservice.api.messages.SignalServiceContent
+import org.whispersystems.signalservice.internal.serialize.protos.SignalServiceContentProto
+import kotlin.random.Random
+
+@Suppress("ClassName")
+class MessageContentProcessor__handleStoryMessageTest : MessageContentProcessorTest() {
+
+  @Before
+  fun setUp() {
+    FeatureFlagsTestUtil.setStoriesEnabled(true)
+    SignalDatabase.mms.deleteAllThreads()
+  }
+
+  @After
+  fun tearDown() {
+    SignalDatabase.mms.deleteAllThreads()
+  }
+
+  @Test
+  fun givenContentWithAGroupStoryReplyWhenIProcessThenIInsertAReplyToTheCorrectStory() {
+    val sender = Recipient.resolved(harness.others[0])
+    val groupMasterKey = GroupMasterKey(Random.nextBytes(GroupMasterKey.SIZE))
+    val decryptedGroupState = DecryptedGroup.newBuilder()
+      .addAllMembers(
+        listOf(
+          DecryptedMember.newBuilder()
+            .setUuid(harness.self.requireServiceId().toByteString())
+            .setJoinedAtRevision(0)
+            .setRole(Member.Role.DEFAULT)
+            .build(),
+          DecryptedMember.newBuilder()
+            .setUuid(sender.requireServiceId().toByteString())
+            .setJoinedAtRevision(0)
+            .setRole(Member.Role.DEFAULT)
+            .build()
+        )
+      )
+      .setRevision(0)
+      .build()
+
+    val group = SignalDatabase.groups.create(
+      groupMasterKey,
+      decryptedGroupState
+    )
+
+    val groupRecipient = Recipient.externalGroupExact(group)
+    val threadForGroup = SignalDatabase.threads.getOrCreateThreadIdFor(groupRecipient)
+
+    val insertResult = MmsHelper.insert(
+      message = IncomingMediaMessage(
+        from = sender.id,
+        sentTimeMillis = 100L,
+        serverTimeMillis = 101L,
+        receivedTimeMillis = 102L,
+        storyType = StoryType.STORY_WITH_REPLIES
+      ),
+      threadId = threadForGroup
+    )
+
+    val expectedBody = "Hello, World!"
+    val storyContent: SignalServiceContentProto = TestProtos.build {
+      serviceContent(
+        localAddress = address(uuid = harness.self.requireServiceId().uuid()).build(),
+        metadata = metadata(
+          address = address(uuid = sender.requireServiceId().uuid()).build()
+        ).build()
+      ).apply {
+        content = content().apply {
+          dataMessage = dataMessage().apply {
+            storyContext = storyContext(
+              sentTimestamp = 100L,
+              authorUuid = sender.requireServiceId().toString()
+            ).build()
+
+            groupV2 = groupContextV2(masterKeyBytes = groupMasterKey.serialize()).build()
+            body = expectedBody
+          }.build()
+        }.build()
+      }.build()
+    }
+
+    runTestWithContent(storyContent)
+
+    val replyId = SignalDatabase.mms.getStoryReplies(insertResult.get().messageId).use { cursor ->
+      assertEquals(1, cursor.count)
+      cursor.moveToFirst()
+      cursor.requireLong(MessageDatabase.ID)
+    }
+
+    val replyRecord = SignalDatabase.mms.getMessageRecord(replyId) as MediaMmsMessageRecord
+    assertEquals(ParentStoryId.GroupReply(insertResult.get().messageId).serialize(), replyRecord.parentStoryId?.serialize())
+    assertEquals(threadForGroup, replyRecord.threadId)
+    assertEquals(expectedBody, replyRecord.body)
+
+    SignalDatabase.mms.deleteGroupStoryReplies(insertResult.get().messageId)
+  }
+
+  private fun runTestWithContent(contentProto: SignalServiceContentProto) {
+    val content = SignalServiceContent.createFromProto(contentProto)
+    val testSubject = createNormalContentTestSubject()
+    testSubject.doProcess(content = content)
+  }
+}
diff --git a/app/src/androidTest/java/org/thoughtcrime/securesms/messages/MessageContentProcessor__handleTextMessageTest.kt b/app/src/androidTest/java/org/thoughtcrime/securesms/messages/MessageContentProcessor__handleTextMessageTest.kt
new file mode 100644
index 0000000000..3d0e9c5ea1
--- /dev/null
+++ b/app/src/androidTest/java/org/thoughtcrime/securesms/messages/MessageContentProcessor__handleTextMessageTest.kt
@@ -0,0 +1,36 @@
+package org.thoughtcrime.securesms.messages
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import org.thoughtcrime.securesms.database.SignalDatabase
+import org.thoughtcrime.securesms.testing.TestProtos
+import org.whispersystems.signalservice.api.messages.SignalServiceContent
+import org.whispersystems.signalservice.internal.serialize.protos.SignalServiceContentProto
+
+@Suppress("ClassName")
+class MessageContentProcessor__handleTextMessageTest : MessageContentProcessorTest() {
+  @Test
+  fun givenContentWithATextMessageWhenIProcessThenIInsertTheTextMessage() {
+    val testSubject: MessageContentProcessor = createNormalContentTestSubject()
+    val expectedBody = "Hello, World!"
+    val contentProto: SignalServiceContentProto = TestProtos.build {
+      val dataMessage = dataMessage().apply { body = expectedBody }
+      val content = content().apply { this.dataMessage = dataMessage.build() }
+      serviceContent().apply { this.content = content.build() }
+    }.build()
+
+    val content = SignalServiceContent.createFromProto(contentProto)
+
+    // WHEN
+    testSubject.doProcess(content = content)
+
+    // THEN
+    val record = SignalDatabase.sms.getMessageRecord(1)
+    val threadSize = SignalDatabase.mmsSms.getConversationCount(record.threadId)
+    assertEquals(1, threadSize)
+
+    assertTrue(record.isSecure)
+    assertEquals(expectedBody, record.body)
+  }
+}
diff --git a/app/src/androidTest/java/org/thoughtcrime/securesms/testing/TestProtos.kt b/app/src/androidTest/java/org/thoughtcrime/securesms/testing/TestProtos.kt
new file mode 100644
index 0000000000..5d2efabcd5
--- /dev/null
+++ b/app/src/androidTest/java/org/thoughtcrime/securesms/testing/TestProtos.kt
@@ -0,0 +1,70 @@
+package org.thoughtcrime.securesms.testing
+
+import com.google.protobuf.ByteString
+import org.signal.libsignal.zkgroup.groups.GroupMasterKey
+import org.whispersystems.signalservice.api.push.ServiceId
+import org.whispersystems.signalservice.internal.push.SignalServiceProtos
+import org.whispersystems.signalservice.internal.push.SignalServiceProtos.DataMessage
+import org.whispersystems.signalservice.internal.push.SignalServiceProtos.GroupContextV2
+import org.whispersystems.signalservice.internal.serialize.protos.AddressProto
+import org.whispersystems.signalservice.internal.serialize.protos.MetadataProto
+import org.whispersystems.signalservice.internal.serialize.protos.SignalServiceContentProto
+import java.util.UUID
+import kotlin.random.Random
+
+class TestProtos private constructor() {
+  fun address(
+    uuid: UUID = UUID.randomUUID()
+  ): AddressProto.Builder {
+    return AddressProto.newBuilder()
+      .setUuid(ServiceId.from(uuid).toByteString())
+  }
+
+  fun metadata(
+    address: AddressProto = address().build(),
+  ): MetadataProto.Builder {
+    return MetadataProto.newBuilder()
+      .setAddress(address)
+  }
+
+  fun groupContextV2(
+    revision: Int = 0,
+    masterKeyBytes: ByteArray = Random.Default.nextBytes(GroupMasterKey.SIZE)
+  ): GroupContextV2.Builder {
+    return GroupContextV2.newBuilder()
+      .setRevision(revision)
+      .setMasterKey(ByteString.copyFrom(masterKeyBytes))
+  }
+
+  fun storyContext(
+    sentTimestamp: Long = Random.nextLong(),
+    authorUuid: String = UUID.randomUUID().toString()
+  ): DataMessage.StoryContext.Builder {
+    return DataMessage.StoryContext.newBuilder()
+      .setAuthorUuid(authorUuid)
+      .setSentTimestamp(sentTimestamp)
+  }
+
+  fun dataMessage(): DataMessage.Builder {
+    return DataMessage.newBuilder()
+  }
+
+  fun content(): SignalServiceProtos.Content.Builder {
+    return SignalServiceProtos.Content.newBuilder()
+  }
+
+  fun serviceContent(
+    localAddress: AddressProto = address().build(),
+    metadata: MetadataProto = metadata().build()
+  ): SignalServiceContentProto.Builder {
+    return SignalServiceContentProto.newBuilder()
+      .setLocalAddress(localAddress)
+      .setMetadata(metadata)
+  }
+
+  companion object {
+    fun <T> build(buildFn: TestProtos.() -> T): T {
+      return TestProtos().buildFn()
+    }
+  }
+}
diff --git a/app/src/androidTest/java/org/thoughtcrime/securesms/util/FeatureFlagsTestUtil.kt b/app/src/androidTest/java/org/thoughtcrime/securesms/util/FeatureFlagsTestUtil.kt
new file mode 100644
index 0000000000..c8348c45ed
--- /dev/null
+++ b/app/src/androidTest/java/org/thoughtcrime/securesms/util/FeatureFlagsTestUtil.kt
@@ -0,0 +1,10 @@
+package org.thoughtcrime.securesms.util
+
+/**
+ * Utility to enable / disable feature flags via forced values.
+ */
+object FeatureFlagsTestUtil {
+  fun setStoriesEnabled(isEnabled: Boolean) {
+    FeatureFlags.FORCED_VALUES[FeatureFlags.STORIES] = isEnabled
+  }
+}
diff --git a/app/src/main/java/org/thoughtcrime/securesms/util/FeatureFlags.java b/app/src/main/java/org/thoughtcrime/securesms/util/FeatureFlags.java
index 7c8a7764ac..0506712420 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/util/FeatureFlags.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/util/FeatureFlags.java
@@ -82,7 +82,7 @@ public final class FeatureFlags {
   private static final String RETRY_RECEIPTS                    = "android.retryReceipts";
   private static final String MAX_GROUP_CALL_RING_SIZE          = "global.calling.maxGroupCallRingSize";
   private static final String GROUP_CALL_RINGING                = "android.calling.groupCallRinging";
-  private static final String STORIES                           = "android.stories.7";
+          static final String STORIES                           = "android.stories.7";
   private static final String STORIES_TEXT_FUNCTIONS            = "android.stories.text.functions";
   private static final String HARDWARE_AEC_BLOCKLIST_MODELS     = "android.calling.hardwareAecBlockList";
   private static final String SOFTWARE_AEC_BLOCKLIST_MODELS     = "android.calling.softwareAecBlockList";