Apart from being the title of The Flash (vol.3) #7, it's also the central theme of this Rogue Profile issue focusing on Captain Boomerang. Writer Geoff Johns began these sorts of between-storyline, villain spotlight issues back in the previous Flash volume and it's good to see him resuming them once again. They give Johns the opportunity to flesh out the Flash's Rogues Gallery as characters while giving him a forum to update and tweak things more to his liking.
The last time Captain Boomerang received this much attention to his origin and background was way back in 1990 in the pages of Suicide Squad #44. In that story, we learn about the early life of George "Digger" Harkness up until the point he becomes Captain Boomerang. We also get the revelation that W.W. Wiggins, the toy manufacturer that hired Digger to be a spokesman for his new line of boomerangs way back in Captain Boomerang's first appearance in The Flash (vol.1) #117, was actually his real father. An interesting way to add something to the character and bring things full circle a bit.
In Johns' take on Boomerang's origin, with art by former Flash artist Scott Kolins, he still learns that Wiggins is his natural father during a trip home for his mother's funeral, but now there's the addition that Wiggins sent him various boomerangs while he was growing up, almost as if Wiggins groomed Digger for his future as Captain Boomerang. Also, there's a brief "deleted scene" set at some point directly after his mother's funeral where he has one last run-in with his abusive father Ian and angrily decapitates him with a razor-sharp boomerang. It's a scene that really should've been given a bit more emphasis, instead of treating it like a simple factoid used to transition back to the present day.
Johns adds a tiny bit more to his Brightest Day mystery by having Boomerang free the imprisoned Professor Zoom, the Reverse-Flash, who apparently is only allowed to go by "Reverse-Flash" these days. Because they were both resurrected by white light, Boomerang wants to know what's coming up in his future and why he's having visions about throwing a boomerang at the heroine Dove. The Reverse-Flash claims that he knows nothing because Boomerang is unimportant to history, but warns that Boomerang will soon blame himself for freeing him. In the next issue, we're scheduled to see a Rogue Profile on the newly-freed Reverse-Flash, so hopefully we'll learn exactly why he runs off after warning Boomerang instead of simply killing him.