The Washington-Reynolds double-act - with Frost's psychological teasing unnerving the anxious greenhorn - and their solid acting makes the first half of Safe House watchable.
But its script - a Bourne meets Training Day on the Western Cape mish-mash - just piles on the predictable twists (oh no, not another rogue element within the CIA!) and it loses its grip as the body-count mounts and the movie heads out into the veldt.
At the beginning of Safe House, Washington comes striding down a street in Cape Town looking a lot like he did as Malcolm X. Things sure have changed round here since he played Steve Biko in 1987's Cry Freedom and the South African setting can be intriguing. If only that it's a rare movie that lets us decide on the greater torture - waterboarding or vuvuzelas?
But when it comes to that aforementioned rooftop run, it's on a one-storey shantytown. Yes, Washington makes a very cool cat on a hot tin roof. But you do end up thinking: "Use the road man, those evil henchmen will see you up there."
Still, Safe House is not as spectacularly bad as Killer Elite. One reason for its dreadfulness is Robert De Niro. He plays Hunter, a hitman-mentor to Jason Statham. After Hunter is kidnapped by a Sheik, Statham's Danny is forced on a mission to kill off the ex-SAS officers who killed the Arab's sons.
The legendary De Niro has been in bang-bang popcorn flicks before. Good ones like Heat and Ronin.
But in this one, despite all that gunfire, he sleepwalks his way through every scene, bar a telling one where Hunter pockets a wad of notes from a briefcase of dirty money.
"I gotta cover my expenses," he quips.
It's his only convincing line in the whole movie. Funny that. Must have been practising it for some time.
Killer Elite is set in the early 1980s, which explains the Mark III Cortinas as well as Clive Owen's moustache and a plot which may remind 80s action movie aficionados a bit of Rambo III.
But no, this is "based on a true story", The Feather Men, by British adventurer Sir Ranulph Fiennes. His since-discredited book claimed British soldiers who served in Oman were later assassinated.
For some reason, an actor playing the writer himself turns up to get promptly shot, which just isn't cricket because as dubious as the book was, he wasn't responsible for the script.
Owen plays an ex-SAS enforcer named "Spike" - wow, stupid name - who is soon on Danny's tail.
When they finally meet up there is some inspired mayhem care of Statham and/or his stunt double.
But Owen, not only moustached but sporting a blinded eye, is also burdened with the film's most hilariously awful lines.
Much of this was shot in Australia with Melbourne substituting, badly, for London.
And when he's not out being a global hitman, Danny has a bush lifestyle block with his understanding Aussie girlfriend. Yes, it's a bit strange when this bang-bang flick turns into a prequel to McLeod's Daughters.
But at least the strong smell of bullshit permeating the rest of the movie seems momentarily apt in the rural interludes.
Safe House
Stars: 2.5/5
Cast: Denzel Washington, Ryan Reynolds
Director: Daniel Espinosa
Running time: 115 minutes
Rating: M (violence and offensive language)
Verdict: Washington and Reynolds' duel helps mediocre action flick
Killer Elite
Stars: 1.5/5
Cast: Jason Statham, Clive Owen, Robert De Niro
Director: Gary McKendry
Running time: 116 minutes
Rating: R16 (violence and offensive language)
Verdict: More evidence of De Niro's squandered talents
-TimeOut