There’s three teams heading into Rassilon’s tomb: The not-quite 1st Doctor  (Hurndall’s fine but he’s no Hartnell) and Tegan, the 2nd Doctor and the Brigadier (team big coats) and the 3rd Doctor and post-K9 and Company Sarah Jane Smith. Out of those I think my favourite team-up is the latter, it’s just very sweet. Oh and Susan and Turlough are left behind in the Tardis (and I don’t care for Turlough) while the 5th Doctor is in the council chambers. The 4th and Romana II are…somewhere, stuck in a triangle (I think thye just took a scene from unaired Shada for the scene we saw).