When Frank manages an escape by using his firefighting know-how to rig electrical wiring, a metal door, coffee, a spraycan and a lighter. MacGyver would have been proud.
Not only that, minutes later he sneaks into the killers apartment to find evidence and manages to outrun the man while being shot at.
When it looks like Shepard is about to kill the younger John, Julia of all people appears out of nowhere and attacks Shepard long enough for John to escape.
Frank shows up to rescue John when he comes face to face with the elderly Nightingale Killer, and he does so with a shotgun in hand, awesome!
Not just any shotgun. It's the very same shotgun Frank used to blow off the killer's hand 30 years ago.
The concept and execution of the parallel fights between Frank and young Shepard in 1969 and John and old Shepard in 1999. Double points for the injuries the former recieves suddenly appearing on the latter, including the
infamous bit where old Shepard's hand twists and malforms into a stump after young Shepard's is shot off by Frank.