It's not an easy film to watch, especially because so many of Jeff's family members are themselves walking disasters. But the performances by Gyllenhaal and Maslany make the ordeal worthwhile.

Gyllenhaal has rarely been better.

With its swelling score and obligatory shots of noble, fluttering US flags, the film buys into the hero narrative wholesale.

For a few nerve-wracking days, the Boston terror attack shook America, yet eventually acted as a spiritual salve that showed the nation’s strength and ability to back a common cause.