In Grayson’s robe pocket is a note that reads,
“Ambrose, you did well with the cart. The attack achieved what
we desired, though the fools who intervened reduced our expected
output. Keep out of sight for now. When things calm down, come
to the dreammaster’s theater for the next delivery.
The undead had nothing of value on them, but Grayson wears a tattered gray Arcanists of the Hidden Veil robe with many small pouches and pockets full of spell components, as well as 25 gp and a pair of onyx rings: a skull ring worth 20gp, and one with silver-painted runes on the inside worth 10 gp. Neither is magical, but the runes on the second one signify danger and death, as confirmed by Legion.
Potential avenues for investigation:
Elsa Whiterose, who runs a mission in the commons who believes she recognized two of the zombies as vagrants who would visit the mission.
Someone named Aerto at the docks who apparently is in the market for bodies of the recently deceased
The halfling, Rollo, who knows that one of the zombies was his friend who was interred properly with the rituals to prevent the Lich King from animating him…so why was he wandering around as undead?