This serial has something of a poor reception within fandom as being 'dull', and I don't understand it. I thought it was excellent. Whilst the ending leaves a lot to be desired and the Doctor seems a bit gullible when he somehow doesn't recognize the Master's voice over the radio in the cargo ship, overall it's a fun and epic space opera for the Pertwee era. Jo Grant is at her greatest here, as she demonstrates how much she has learned from the Doctor, and Roger Delgado's last performance as the Master is every bit as cold and commanding as you would expect. This serial deserves more love.