Not a great episode, but reliable performances This is not a great Perry Mason mystery, as it has a few too many coincidental events, and characters behaving in non-credible ways.
But for fans of classic 1960s TV, the show is filled with familiar and reliable actors, doing their level best with the material.
First is Billy Mumy, as noted by several previous reviewers, who was possibly the most dependable child performer of the early 60s. Here he is a good kid, trying to figure out who to trust with what he has and what he knows. One interesting thing is his interaction with Perry Mason. Looked at in the light of 2019 sensibilities, the scene where Perry offers Miles a ride home from the theatre might have a certain "creep" factor. (Miles doesn't yet know Mason, and declines.) But back in the day, it was pretty much innocent.
Constance Ford is on hand as Sylvia, to turn in her patented "kicked puppy" performance. If you pay attention, you can almost imagine her saying "Yes, Uncle Simon". The most disturbing thing by the end is the thought that young Miles will remain in her care.
One of my favorite things watching Perry Mason reruns is the chance to see Denver Pyle before he locked into his trademark "country" personna so familiar from the likes of "Dukes of Hazard" or "The Life and Times of Grizzly Adams". Here he's a businessman, with nothing particular of the "rural" stereotype about him.
One oddity is Russ Conway as the Deputy. Conway was ubiquitous in roles as police officers, sheriffs, businessmen (honest or conniving) and other authority figures. He's fine here as well, but unlike most appearances his character isn't really important to the plot. He's just a Deputy - never a suspect, major witness or anything else. Very strange for Conway.