The Doctor and Clara receive a phone call from Rigsy, who informs them of strange numbers that have appeared on the back of his neck that are counting down with no memory of how he got it. After examining him, they trace his movements to a trap street in present-day London that houses extraterrestrial refugees. They then discover Rigsy was sentenced to death by Me, [N 2] the street's mayor, for murdering an alien called Anah and that Rigsy will be killed by an alien raven when the tattoo, known as a Chronolock, reaches zero. Clara discovers that the Chronolock can be transferred to a willing recipient and takes it from Rigsy, believing that Me will spare her, buying them more time. The Doctor realises from the medical data in the stasis pod Anah is stored inside that Anah is still alive; Me made a deal with an unknown party to have the Doctor transported far away to keep the street safe. As the Chronolock has been passed on to Clara, Me cannot remove it and Clara cannot be saved. Clara pleads with the Doctor not to take revenge for her. The raven kills Clara, and the Doctor is teleported away.