Ask for Amulette to show her mark

You thought that Amulette seemed like the confident sort who wouldn't mind showing off a bit for a crowd like this. As such, you leaned toward the back of the carriage, whispering into the blankets.

"Keehehehe, you're that eager to eye my exciting emblem, are you? Who knows where it's hidden, hmmm?" she giggled. "Very well. This will be a worthwhile lesson to whet your wisdom as our erstwhile leader."

"Who's that in the back of the carriage? You allow a saintess to travel like this? Some squire!" Mertz scoffed, dropping his arms to his sides as he circled the cart. Slowly, he pulled free his short-sword, then began to poke at the back of the cart with his pommel. "You there. Out of the cart. If you're truly a saintess, let us see your- Gyah!"

What popped out from the cart was not Amulette in a proper state of undress to show off the mark of Geod's touch, as you'd been hoping. Instead, what emerged from the blankets was a summoned skeleton, draped momentarily in black fog before becoming crystal clear. A voice came from underneath it: "How's this? Not a scrap of silk left to shield my sublime skin-- and not a scrap of skin left to conceal my sultry skeleton!"

"N-Necromancy!" Mertz cried out, falling backwards and dropping his swords. The other guardsmen were still standing and instead placed hands on their blades. "What are you waiting for?! Apprehend them! Sieze the whole cart!"

That was your queue to get moving. This quest couldn't afford to fail, not this early!

As you set the horses into high gear, barreling past guards and knocking a few to their asses to join their commander, Amulette laughed and kicked her feet in the back of the cart. "Keeeehehehahaha! I did warn you of my whimsical wishes, Squire! I told you that there would be nothing but a necromancer's nonsense!" she reminded you. "But seriously, how did you think those thoughtless thugs would respond to the revelation of a rival demon, reformed or otherwise? Twas all frightfully fun, but future fights can be avoided if you demonstrate more discretion."

Whatever the case, the investigation would doubtless be a bit harder now that the majority of the towns' guards had their alarms raised.