If you haven’t seen the show, the format is this: champions from other quiz shows form a regular, daily team and face off in a series of rounds with various challengers. Should the challengers beat the Eggheads, then they get a cash prize. Occasionally the Eggheads rotate their team members but they come from the same pool of 6 or 7.
Competing against the Egghead regulars will be the Sixth Doctor Colin Baker alongside Frazer Hines (Jamie McCrimmon), Louise Jameson (Leela), Katy Manning (Jo Grant) and John Leeson (voice of K-9.)
The special will be in aid of charity and will air Monday 20th December at 6pm.
(via Doctor Who Online)