Question for SPQR fans

Because of an odd lending rule at my local library, I just this weekend got hold of **John Maddox Roberts’ **most recent novel in his Roman mystery series SPQR.

I was very surprised about the amount of time and events he skipped between this one – Year of Confusion – and the one before – Oracle of the Dead.

He went from just before Caesar’s crossing of the Rubicon to the year before Caesar’s death. And it also seems Decius’ father, one of the series best characters, died during those years.

It seems an odd time to skip, considering all that happened. Anyone else think so? Or know why?

Or just want to chime in on an entertaining series of books?