Ella's story in "Pretty in Blue" has Marcus giving up on finding Cecelia in New Wonderland only after the locket stops working. But Alice was present at her death and recounted it to Ella. Yet it is after Marcus returns from Wonderland that Rapunzel traps Gothel, leading to Alice's birth. So, time travel? Only other explanation is that the locket stopped working because she took it off rather than because she died and that her death wasn't until much later, but that wasn't stated and wasn't the implication I got.