Doctor Who: The Spear of Destiny: 08/14/16
Doctor Who: The Spear of Destiny by Marcus Sedgwick is the third in the Doctor Who short stories published in conjunction with the show's 50th anniversary. As it is the third book it features the Third Doctor and his second companion, Jo. Together they need to retrieve a spear that has dangerous special abilities.
When popping into the museum where it's housed in the present day (this present being the 1970s to be contemporaneous with that regeneration of the Doctor on Earth) goes wrong, the Doctor and Jo must travel back in time to a much earlier reported spotting of the weapon. Of course this ultimately leads them to a trap involving the master as many Third Doctor plots do. This is not the more modern day mincing nancy-boy master nor the Victorian styled older lady "Missy", but the goatee sporting, evil, cackling master who is just a hair away from being Snidely Whiplash. (Can you tell I don't like the Master in any of their forms?)
The Third Doctor is one of my favorites, even with his ridiculous (and ridiculed in this book) Inverness Cape. He drove an awesome old car, Bessie, got stuck on Earth for quite some time and had to work for (or with depending on whom you ask) UNIT, and was basically bad ass. He had two companions: Liz Grant, a brilliant scientist, and Jo Grant, a much younger companion who mostly due to her age, I suspect, was written as an affable bubble head.
Unfortunately for this novella, Liz's time with the Doctor is mostly during his grounding on Earth. She consults for UNIT much as he does. Sedgwick's story, though relies on the TARDIS being functional (as well as it ever is). The title, though, brings to mind the first adventure the Third Doctor has, Spearhead from Space.
In terms of the final solution to the problem of the spear, it's more akin to an excellent Fourth Doctor episode, City of Death (1979) where the Doctor and Ramona uncover a mystery spanning several different moments in time. In the process of saving the world and ending the time loops, they create a number of fake Mona Lisa paintings.