Plot -When the TARDIS spins out of control, landing in the Doctor’s past time line somehow. The Tenth Doctor knows he may be going to run into one of his past selves. The Tenth Is surprised though when he runs into the 4th Doctor, but the 4th Doctor is puzzled about who the Tenth Doctor is at first, until he sees Ten’s TARDIS. Knowing who he is the 4th Doctor asks for assistance.
Tenth Doctor
Tenth Doctor