Unearthly Woman

This directly ties to unearthly child, Ian and Barbera both appear as river is teaching geography at coal Hill for some reason.

Susan sounds too young despite the fact this takes place in 1963. River casually hints at Ian and barbera's futures as the 3 of them do detective work about 2 mistreated foster children, Lloyd and shella. The first doctor makes a brief cameo.A Nightstalker is also present, taking Shella's body to survive the day, only killing people in the night. They desire to kill the doctor in his younger vulnerable state in the junkyard. Ultimately Susan helps River to repel the Nightstalker into another dimension.

River's last act is to refence the future events of Ian Barbera and Susan. Susan says an obligatory doctor who. The first Doctor doesn't put up with River's nonsense.