Corridors of Death is the first in the Robert Amiss series by Ruth Dudley Edwards. I'm quite fond of this series, and was lucky enough to pick up most of these titles back in pre-agency/Fictionwise days, and have them transferred to BN when FW went out of business. This series reminds me a bit of my absolute most favorite Hilary Tamar series by Sarah Caudwell for the bone dry British humor (humour), a bit of Amanda Cross/Kate Fansler for the academic bent of many of them, a bit of R.B. Dominic (aka Emma Lathen)/Ben Safford on the political side, and is just overall quite enjoyable. I do mostly disagree with Edwards's politics, but mostly she doesn't shove them in your face, except possibly in the last couple of books in the series, and I found I could easily overlook the politics most of the time.
Anyway, after a long-winded post...
Corridors has dropped to $0.99 at Kindle US.
link:
https://www.amazon.com/dp/B07VRLDWB9