Task: Question Generation
Input (English): Passage: Late one night at the Russell Square station in the London Underground, university students Patricia and her American exchange student boyfriend Alex find an unconscious man collapsed on the stairwell. Fearing the man may be diabetic, Patricia checks his wallet and finds a card that reads James Manfred, OBE. Alex and Patricia inform a police officer about Manfred, Alex and the officer return to the stairwell to Alex's surprise find that Manfred has vanished. Inspector Calhoun is assigned to look into the disappearance. Calhoun antagonistically questions Alex, who asserts the man was a drunk, and suggests he and Patricia robbed the man.
While discussing the case of the missing Manfred, Calhoun's colleague tells him about the history of the London Underground, particularly the Victorian railway workers who constructed the tunnels under dire conditions, and an urban legend that a group of descendants who survived an 1892 cave-in still live below ground in an abandoned section of the tunnels. Meanwhile, one of the last surviving members of a family of these railway workers watches his female companion die; they have survived in the underground by resorting to cannibalism of the railway patrons. In an empty chamber, Manfred's body lies, mutilated. The man laments the woman's death, as he is now left in complete solitude. The man goes into a rage and brutally murders three Underground maintenance workers in, taking one to his lair.
Calhoun remains suspicious of Alex and Patricia, and calls Alex in for repeated interrogations. After seeing a film one night, Alex and Patricia take a train home and get off at Holborn station. While de-boarding, Patricia realizes she forgot her textbooks on the train. Alex attempts to retrieve them, but the doors close before he can exit; just as the train leaves, Patricia yells through the window that she will meet him at home. Once the train exits the platform, Patricia is attacked by the cannibal man and incapacitated.
Output (English): What did Alex try to retrieve on the train?