Wives’ deadly game in postwar London

When two old girlfriends meet again by chance on the streets of postwar London, it marks a new beginning in their relationship and perhaps the beginning of the end for their husbands in “Dead Gorgeous,” the summer season premiere of PBS’ “Mystery!” franchise (9 p.m. Sunday on KCET).

The entertaining two-hour effort is shot through with generous dollops of dark humor as Antonia Ashton (Helen McCrory) and Rose Bell (Fay Ripley) form an unlikely alliance born out of a shared desire to shed the spouses they met during the war.

Brassy beauty Antonia hooked up with Czech refrigerator magnate Hector after jumping into his arms during a wartime bombing.

Was romance in the air?

“Not really,” explains Antonia. “But I felt terribly safe snuggled up against his wallet.”

Meek and mousy Rose somehow snagged a flashy combat hero with a ladies’-man reputation.

When Antonia asks how she landed the philanderer, Rose answers, “I don’t know, by holding out I suppose. I just kept saying no.”

“You must be the only one who did,” marvels Antonia.

But when Rose is beaten by a drunken Barry and then finds evidence that he’s hiding a second family, she grows desperate, although her religious background precludes divorce.

Antonia, meanwhile, is increasingly repelled by the mere sight of Hector and tells him so, but he refuses any solution that would separate him from his money.

Antonia briefly fantasizes about Hector falling victim to some unforeseen catastrophe, but the dream offers scant comfort.

“The trouble with accidents is that you never know when they’re going to happen,” she says forlornly.

So Antonia pushes forward with a deadly plan to free the two women from their husbands for good.

But a nice twist ending offers a surprise for everyone.