Staying Behind: Brand's Choice

While Cooper returned to civilization, Amelia Brand went to the final planet.

Plan B

She sets up the camp, executing Plan B to ensure the survival of the species via population bomb.

The Reunion?

The movie ends with Cooper stealing a ship to go find her. Acknowledging that she is out there, alone, in a new galaxy.

Chronological Timeline

timeline
    title Interstellar Mission Timeline
    Earth's Decline : Dust storms and blight : Cooper finds NASA coordinates : NASA reveals Plan A and B
    The Launch : Endurance departs Earth : Gravity assist around Mars : Entering the Wormhole near Saturn
    Miller's Planet : 1 hour = 7 years Earth time : Tidal wave disaster : Doyle dies
    Mann's Planet : Dr. Mann's betrayal : Romilly killed in explosion : Docking with the spinning Endurance
    The Singularity : Cooper enters Gargantua : Tesseract sequence : Communication through the watch
    The Resolution : Murph solves the gravity equation : Cooper Station established : Cooper reunites with elderly Murph

Further Reading

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