Remember When was written by Nora Roberts and J.D. Robb.
Who are the same person.
More specifically, J.D. Robb is a pseudonym of Roberts, a very popular romance writer. The pseudonym was never that secret—I forget how exactly I came across the first when it was originally published, but it was in connection to Roberts—and recently the covers have stated that they’re by Roberts writing as Robb. Presumably this hardcover is just another marketing step.
Anyway, the concept is that Roberts wrote the first section. This is set in the present day and concerns the aftermath of a diamond heist; there’s been a falling-out among thieves, an insurance investigator is on the case, and luuuuv is in the air. The problem with the first half, besides that the two main characters fall in love really quickly, is that the reader knows that things aren’t going to be wrapped up fully: there has to be something left that leads Eve Dallas, J.D. Robb’s protagonist, to investigate a linked crime fifty-odd years later. And indeed, the loose thread is not entirely plausible.
It also suffers in comparison to the second half, at least to me, because the J.D. Robb books have well-established characters that I care much more about than the ones in the first half. Mind, the second half isn’t perfect; there’s an annoying little continuity error that makes the police characters look much stupider than they actually are. It’s a problem with the series overall, unfortunately, though it’s not entirely surprising considering how prolific Roberts/Robb is (two books a year as Robb, and at least two as Roberts, generally). Hey, guilty pleasure, you know the drill.