It's not a setback.

Exploration Stage: Artifact Bank
From: Mr. Jenkins
Description: Now all that was left was to find the final talisman to make the switch. The main goal of the guardians was to ensure the prosperity of the city. The observation journal fragment has a picture of the moon repeatedly drawn in the margin. This is a symbol of growth. You should try to find a talisman similar to this one.
Completed: Excellent! You have found the Talisman of the Three Night Moon. How impressive. Turn it over and it becomes a symbol of the 28th, or darkness and decline. The moon is a symbol of intuition, and all of the guardians listened well to themselves.