This could be told in flashbacks, time-travel, memories, etc. As long as you are jumping between two points in time, it fits the challenge!
Recommendations:
Revolution - Jennifer Donnelly (teen/adult) Wonderstruck - Brian Selznick (middle grade) The Art of the Swap - Kristine Carlson Asselin and Jen Malone (middle grade) The Boy from Tomorrow - Camille DeAngelis (middle grade) Hotel on the Corner of Bitter and Sweet - Jamie Ford (adult)
We just finished The Art of the Swap from the Gilded Age reading crate. Both my 7 yr old and I loved it! The way the characters noticed differences in their time periods, the problem solving and the fact that so many bits & pieces were actually based on true events were my favorite parts.
Recommendations:
Revolution - Jennifer Donnelly (teen/adult)
Wonderstruck - Brian Selznick (middle grade)
The Art of the Swap - Kristine Carlson Asselin and Jen Malone (middle grade)
The Boy from Tomorrow - Camille DeAngelis (middle grade)
Hotel on the Corner of Bitter and Sweet - Jamie Ford (adult)