Blood Feud is the first in Mike Lupica’s continuation of Robert B. Parker’s Sunny Randall series. I haven’t read any of Lupica’s Sunny Randall continuation books, but FWIW I did read the first (Fool’s Paradise) in his continuation of Parker’s Jesse Stone series, and enjoyed that one. Blood Feud has dropped to $1.99 at Kindle and Kobo US right now (March 3, 2021).
Payback is the third in Mike Lupica’s continuation of Robert B. Parker’s Sunny Randall series. It’s $2.99 today at Kindle US as part of today’s Daily Deal, and matched at Kobo US.
Kindle US: https://www.amazon.com/dp/B08FZLGZDM
Kobo US: https://www.kobo.com/us/en/ebook/robert-b-parker-s-payback-1