This week’s ComiXology back-issues include Flash #72-73 and Impulse #33-34.

Flash #72 concludes the two-parter with The Alchemist, a short-lived successor to Dr. Alchemy, and is also the issue in which Wally West and Linda Park start dating. Flash #73 features the return of Jay Garrick to the title after the Justice Society’s years in limbo, and what was at the time a shocking last page that led directly in to “The Return of Barry Allen.”

The Return of Barry Allen itself is already available, launched during the Flash 101 sale last year, as is the following storyline, “Back on Track,” in which Wally teams up with Nightwing and Starfire. That means that as of this week, the first 83 issues of Wally West’s Flash series are all available online. No doubt next week ComiXology will jump ahead to #84.

I don’t remember anything about Impulse #33, and as fun as the cover is, it doesn’t jog my memory of the contents. The title is “Time Out,” so it might be the one where Bart’s school’s new guidance counselor calls Max and Helen in to go over Bart Allen’s guardianship. (It’s funnier than it sounds.) ComiXology describes it as featuring the return of White Lightning, and the kids dealing with the missteps of the school’s new social worker.

Impulse #34 is the first half of “The Devonian Age,” a story in which Bart and Max Mercury get caught up in a time travel experiment gone wrong (don’t they always?) and have to try to repair history from the butterfly effect.