Mrs. Pitt is the mummy's very first victim. 66.0 seconds is the time she had before the creature killed her. Yet she was the only one that could see it.
The Doctor and Clara are having one last hurrah. She's decided she can no longer travel with the Doctor and the Orient Express is their last trip.
Little do they know, there's a mummy aboard stalking and killing the train's passengers. So much for a quiet and not dangerous adventure.
The Doctor spots Prof. Moorehouse and the discuss the most interesting thing about the Foretold. It's not the time limit given before it kills you. It's not the fact some claim there's a secret word that makes it stop. It's the fact you can't run from it. It's always right there behind you.
Video footage of the first victim confirms the 66 second myth. The lights flicker as well. The Doctor figures out the passengers themselves are the strangest part of this entire situation. Experts in alien biology, mythology, physics. They are too perfect a team brought together in one place.
The train's computer, Gus, is behind everything. He's been programmed to figure out the Foretold's nature and capture it. Who programmed him?
Maisie Pitt, in mourning for her grandmother, is the next victim. The Doctor asks Clara to bring her to him. Her tells Maisie to focus her grief, trauma, resentment and captures it transferring her emotions to himself. The mummy now appears to him. Start the clock!
Marking under the mummy's bandages are identical to the ones on the scroll that attracts it to specific locations. The markings are a flag.
The Doctor now understands the Foretold was a soldier, wounded in battle thousands of years ago. "We surrender" the Doctor tells him and the mummy salutes. "You're relieved soldier" the Doctor says then the mummy dissolves into a pile of dust.
A.I. Gus thanks the Doctor but unfortunately survivors are not required. He begins to remove the oxygen from the train.
Luckily the Foretold's tech included a teleportation device. The Doctor manages adjust it and whisk everyone back to the Tardis before the Orient Express explodes.
Clara speaks to Danny and soon realizes he's totally fine with the Doctor and their travels. "To hell with the last hurrah, let's keep going" she says.