Unfortunately, Grissom's search for Ashley Riot in the labyrinthine paths of the Snowfly Forest leads him right to the wrong quarry. Severely wounded after a battle with Sydney Losstarot, he attempts a summoning, and fails. It is possible that he meets his death at that moment and is reanimated by the powers of the Dark. In any case, he staggers to his feet and completes the summoning, bringing forth a dark knight to do battle with Sydney and the intervening Riskbreaker.
While the priest and the dark knight make a fearsome team, so do the cultist and the VKP agent. Both Grissom and his called ally fall to the combined forces of Riot and Losstarot.
Grissom's last word on this side of the grave is "Father."
From his body Ashley retrieves the Swan Song amulet and Grissom's silver shillelagh.
Some time later, Ashley Riot happens upon two other commanders in the Crimson Blades: Neesa and Tieger. The warriors have discovered Grissom's corpse-- but at the top of the Bread-peddlar's Way in Undercity West. After Ashley tangles with the pair he returns to the stairwell, and finds the two Blades staring in confusion as Grissom struggles to his feet.
Unaware of his recent demise, Grissom still claims revenge on the Riskbreaker, only to have his two comrades regretfully refuse to aid him. Neesa informs Grissom of his fate, and he falls to his knees in dismay.
...then the walls begin to speak...
It is possible that with the fall of Leá Monde, Grissom's soul is able to escape the paling that holds the dead of the city in thrall. Whether or not this peace is granted him, his tomb is in the once-sacred corridors of Sanctum, where he is last seen with Tieger as the walls tumble down.
