Berlin Game is the first in the Bernard Samson series by Len Deighton. A Penguin Modern Classics (!) version of Berlin Game is on sale for £0.99 at Kindle UK today, as part of today’s Daily Deal. Per SYKM, this was a finalist for the 1983 Gold Dagger Award.
Buy at Kindle UK
Spy Hook is the fourth Bernard Samson book. It’s £1.99 at Kindle UK right now: https://www.amazon.co.uk/dp/B08QV6X442
Charity is the ninth and final Samson book. It’s £0.99 right now at Kindle UK: https://www.amazon.co.uk/dp/B08QV76WHW
Three Samson book are £1.99 each in the UK right now:
Mexico Set, #2
Kindle UK: https://www.amazon.co.uk/dp/B08QTQQ9M3
Kobo UK: https://www.kobo.com/gb/en/ebook/mexico-set-3
Spy Hook, #4
Kindle UK: https://www.amazon.co.uk/dp/B08QV6X442
Kobo UK: https://www.kobo.com/gb/en/ebook/spy-hook-2
Charity, #9
Kindle UK: https://www.amazon.co.uk/dp/B08QV76WHW
Kobo UK: https://www.kobo.com/gb/en/ebook/charity-33
Be careful though, there are some other e-book versions published by HarperCollins, rather than Penguin, that have also been on sale in the past. So check carefully beforfe you buy!