I love Witch Mark. It’s imo one of the most underrated New Adventures, with lots of atmosphere, a really fun take on the “door to another world” genre that I think stands on its own merits as that even apart from being a Doctor Who story.
(I wish I were reading it now instead of Dragons’ Wrath lol, which is currently living up to its name by draggin’ along, much to my wrath 
I really hope the later Benny books are better than this 
)