Bruce Willis as is presumably past retirement age for a freelance vigilante. His mission in "A Good Day to Die Hard" is a surprise: he didn't fly to Moscow to battle nasty Russians. He went to reconnect with his estranged son, who mysteriously turned up in a Moscow prison.
Far from the black sheep screw-up we're led to assume, McClane's son Jack (Jai Courtney) has been working as a CIA operative. He just cut off his whole family without explanation, that's all! There's a daddy-shaped hole in his heart because Pops missed out on his childhood to chase bad guys. This movie's entire plot could have been prevented by a few backyard games of catch. (Oddly, McClane's daughter harbored no cliché resentment, as she cheerfully drove Dad to the airport.)
So Jack's arrest was a fake-out to let him testify against some Russian politician. But this irks the Bad Guys, who bomb the courthouse before the trial and set off the remaining 80-odd minutes of racket, which are mostly comprised of chase scenes and tenderness between the Senior and Junior McClanes.
The father-son reconciliation was so mushy that it practically dripped off the screen. The McClanes profess mutual love while cradling automatic assault rifles. They'd have to blow up all the property in the world to get away with that sort of cheese.
Not that there's much else to get emotionally invested in: the villains are a bore, and their motives are tedious. This time around, McClane's catchphrase is a dad joke uttered whenever the plot thickens: "I'm supposed to be on vacation!"
Ugh. Isn't it so embarrassing when your dad tries to fight your international security battles for you?