You could even cover it in a short story in Compendium 3, to keep from having to work it into the next book.
Something like Ondreg the Giant 🙂 & Veleslava (also MIA) being tasked with checking on another Mithraic shrine south of Rome & things getting out of hand. Senka shows up after the China battle, ready to punish their lazy asses, but when she sees how broken up they are, just starts laughing.
Might be easier than interrupting the next books narrative.