Antony Maitland skips the courtroom theatrics this time and goes undercover to solve a series of murders in a Top Secret defense facility. This is an older title (1963) written in the mannered traditional British style; if that is your "cup of tea," you should really like this book as well as the many others by Sara Woods.
I recently began reading Sara Woods's Anthony Maitland series from the beginning. While not originally intended as "period" pieces, they now have a foot in that genre because they were written 50 years ago! It was a different world -- no personal computers, no cell phones, and the pall of the cold war very real.
The books are very well written, but the reading can be a little slow going because of the formality of both the spoken and written word of this era. I also found "Error of the Moon" somewhat difficult to sort through because nearly all of the suspects were men! At times, I couldn't remember which scientist was which. In the end, I would still recommend "Error of the Moon" as a greate example of the type of British mystery written in the late 50s/early 60s.
The next book in the series, "This Little Measure," is even better!