Rescue the Illithid's Captive is a quest in the Prologue of Baldur's Gate 3. It can be started by approaching Shadowheart's Mindflayer pod on the Nautiloid.
This quest is not available if the player chooses Shadowheart as their Origin.
Objectives
Objectives and journal entries may vary pending story decisions and outcomes.
Find a way to release the captive.
We encountered a survivor, trapped inside one of the pods aboard the nautiloid. Perhaps we can find a way to free her.
If the player character found an Eldritch Rune: We found an Eldritch Rune. It may help us to rescue the captive half-elf.
Talk to the half-elf.
If the player character used the Eldritch Rune: We opened the pod using an Eldritch Rune, and freed the captive. We should speak to her.
If the player character passed a Strength check as a Barbarian: We forced the pod open using our brute strength, freeing the captive. We should speak to her.
Quest Completed!
If the player character recruits Shadowheart: We learned that the survivor aboard the nautiloid is called Shadowheart. She joined us.
If the player character does not offer for Shadowheart to join them: We learned that the survivor aboard the nautiloid is called Shadowheart. We decided to go our separate ways.
If the player character does not speak to Shadowheart after freeing her: We freed the captive aboard the nautiloid from her pod, but left her behind.
If the player character does not free Shadowheart: We left the captive inside the pod, and escaped the nautiloid without her.
Walkthrough
After the first imp fight on the nautiloid, the player character will enter a room containing some unconscious cultists and a large panel. Further back in the room is a mind flayer pod, where Shadowheart is trapped and thudding against the glass.
If speaking to Shadowheart, she will suggest trying the panel next to the pod to try and open it. Interacting with it will reveal that it has an empty socket.
The required rune is the next room to the east. At the far end of the room is a raised platform with a dead thrall, who can be looted to find an Eldritch Rune. Returning to the pods panel with this rune, it can be inserted and used to control the pod and free Shadowheart.