‘Perry Mason’: Here’s What’s Going on With George Gannon

(This article contains spoilers for HBO’s “Perry Mason” through the episode that aired July 5) “Perry Mason” is a slow-burning noir thriller of the sort that HBO is so fond of, and the first two episodes kind of eased us into this mystery about a baby that was kidnapped for ransom and ended up murdered. But the third episode, dubbed simply “Chapter 3,” took us fully into the weeds of this story, and it can be tough to sift through it all. At the…