While trying to fix the TARDIS, the Doctor notes another TARDIS inside the control room - the TARDIS has materialized inside itself because it was looking for the safest place possible. A second Amy then enters through the TARDIS door.
The other Amy reveals that she is from a few moments in the future. The other Amy knows what to say and do because she is repeating what she heard herself say earlier on. This ultimately helps the TARDIS regain normal flight.
