"Part Six: Collision Course", Part 5 by Jonathan Morris , Matt Fitton , John Dorney , Guy Adams , James Goss , Peter Davison , Tom Baker , Karen Gledhill , Lisa Bowerman , Hugh Ross , Pamela Salem , Sylvester McCoy , Sophie Aldred , John Heffernan , Louise Jameson , Lalla Ward , Ingrid Oliver , Georgia Tennant , Tim Treloar , Simon Williams , Colin Baker , Jemma Redgrave , Katy Manning , India Fisher , Alex Kingston , Paul McGann & Anna Hope