This particular room was shared by Ace and a science geek called Abner Apple. The guy was a professor, despite his youth. But that wasn’t so unusual here on the Hill where it seemed everyone had a doctorate –with the possible exception of the Doctor.
Getting towards the end of the Seventh Doctor novels now, this was actually the 76th and last of the Past Doctor Adventures published between 1997 and 2005. It's sort of appropriate that the last book in the series should have been written by the last script editor of Old Who sixteen years earlier, and it's a bit of a callback to earlier times, the Doctor and Ace here being definitely from shortly after The Curse of Fenric (which is similarly set during the second world war) rather from the New Adventures. Views on this from fandom seem to be mixed, but I rather liked it; the Tardis arrives in Los Alamos in 1944, in time for the Doctor and Ace to prevent history from being rewritten by sinister forces attempting to prevent the Manhattan Project, dealing with bone-headed security agents, unwittingly meddling time-travellers and bogus Japanese agents. The settings are decently realised, though I'm sure that people who know the locations could pick holes in them, and the denouement gratifyingly gonzo after the reader spends the first three quarters of the book wondering what is going on. One can imagine the writer mentally seeing this on the screen rather than the page. A good finish to the series, but I still have the Telos novella Companion Piece and the earlier PDA Bullet Time to go before I say farewell to Seven.