Depths of Deceit

is the tenth episode of the first season of The Legend of Vox Machina. After Percy confronts his old nemesis, Dr. Anna Ripley, a tenuous partnership is struck. Despite Percy's protests that she can't be trusted, Vox Machina brings Ripley along. She leads them through the traps under the castle, but soon the team is double-crossed by one of their own.

Plot summary
Percy continues to train his gun on Anna Ripley as he flashes back to memories of her shooting Cassandra with arrows during his and Cassandra's attempted escape, and then earlier, to Ripley torturing him for the Briarwoods. Keyleth tells Percy to wait, and he shoots the gun but hits the wall instead of Ripley as Cassandra pushes the barrel away. She steps in front of Percy and tries to prevent him from shooting again, and Vex asks who the woman in the cell is. Percy tells Vox Machina about Ripley and threatens to kill her again but Ripley tells him she can provide information. Cassandra, to diffuse the situation, recommends an interrogation. Vax begins to pick the lock, as Scanlan brings up the smoke that seems to envelop Percy during his moments of stress.

Pike offers to try to determine the cause of the smoke, and, with Percy's permission, determines that the source is demon. Percy says he will continue on and deal with it later. Keyleth presses him, and Percy swears on his family name.

During the interrogation, Ripley tells the party that she is merely an engineer and that the Briarwoods her patrons, but she objected to their overall goals, and when she attempted to leave, they imprisoned her. She explains that the Briarwoods will be in the ziggurat, preparing for their ritual. Scanlan verifies this based on his reading of Delilah's book. Ripley also tells Vox Machina that the ziggurat is beneath the castle, which Keyleth can confirm, having sensed it through the Sun Tree. Cassandra believes Ripley and tells Percy this, but Percy is still skeptical and threatens Ripley again. Cassandra entreats him to trust her instead, and Ripley offers to lead the party to the ziggurat. Percy first searches her bag, and finds a rudimentary pepperbox pistol, which he does not permit her to keep.

As this is happening, on the ground in Whitestone, Keeper Yennen leads a charge of the rebels against the guards. Vox Machina, meanwhile, continues through the underground halls. Ripley tells Percy about her work on the ziggurat and her use of residuum in its reinforcement. As they walk, Percy trips one of Ripley's traps and she prevents him from being injured by it, then tells him she should lead the way. Pike and Grog talk about Pike's spiritual journey, Vex and Vax talk about Vax's confession to Keyleth, and Ripley attempts to appeal to Percy as an "intellectual equal" as the group continues to the De Rolo family catacombs.

In the tomb, various deceased de Rolo ancestors have risen due to Delilah's magic and attack the party, who fight them off. In the fight, Ripley picks up a sword and Percy threatens her again until she drops it, although she tells him that she is not the primary threat. Grog then opens the heavy door to another chamber. As the party continues, Vex notes that she is also suspicious of Ripley, and Scanlan asks Keyleth and Grog if it would make more sense to take legal action against the Briarwoods instead but Percy insists that they must end the Briarwoods' plans now.

The party comes upon a room for residuum refining, and Ripley tells them that this was specifically Byron Anders' responsibility when asked for more information. Keyleth notices a drain. As the party talks, Cassandra's name appears on the blank barrel of The List and Percy turns to notice her in the opposite doorway. She presses a button to lower a transparent green wall. Vax is able to slip under it before it closes, and threatens Cassandra with a dagger as she does the same to him with a rapier. As he does so, Sylas Briarwood, along with Delilah, approach and praise Cassandra for her work. Vax attempts to attack them but Sylas quickly enthralls him. Percy asks Cassandra why she betrayed him, and she responds that it's because he left her when they escaped, and that she is now a Briarwood. As she speaks, her eyes flash, revealing she too is under Sylas's control. Percy collapses in despair.

Pike accuses Ripley, who denies any involvement, and the Briarwoods taunt her. Vex threatens the Briarwoods as well, but they only ask Vax to press a button, then walk away with Cassandra following. The button seals up the drain Keyleth had previously spotted and the room begins to fill with acid. Vex begs Vax to return to his senses, but he leaves as well. Vex recommends they seal the pipe, and Keyleth tries to break it with vines, but after a moment the pipe merely springs more leaks. Grog and Pike attempt to break down the wall and also fail. As the room continues to fill, Scanlan casts Scanlan's Hand and everyone jumps on, with Grog picking up a catatonic Percy. Vex slaps Percy to get him to break out of it so they can save Cassandra and Vax. He locates the device that will raise the green wall, and determines there are three switches. With Pike and Ripley's help he realizes the final switch is in the drain, covered by the acid. Keyleth protests but Grog strips naked, leaps in, and swims down to pull it, which raises the door and drains all the acid just as Scanlan's Hand fades. Pike heals Grog, and the group continues on towards the ziggurat.

At the ziggurat, Delilah notes that they have two potential blood sacrifices - Cassandra and Vax - for the ritual.

Cast
End credits list main cast, then guest cast in alphabetical order.

Vox Machina

 * Keyleth
 * Percival de Rolo
 * Scanlan Shorthalt
 * Grog Strongjaw
 * Pike Trickfoot
 * Vax'ildan
 * Vex'ahlia

Returning

 * Cassandra
 * Anna Ripley
 * Delilah Briarwood
 * Sylas Briarwood
 * Keeper Yennen
 * Lord de Rolo
 * Lady de Rolo

Quotations
Pike: Still hanging low, buddies. Grog: Ooh! then, I'm good. Let's go. (realizes he's naked) Oops, forgot my drawers.
 * Grog: Oh, great! Percy's broken! C'mere, ya limp noodle!
 * Percy: (to Anna Ripley) At the moment, you are the luckiest person in Whitestone, because you're at the bottom of my list.
 * Grog: (after Pike heals his acid burns) Is... is Captain Winky still there?
 * Delilah Briarwood: (about Vax and Cassandra) The ritual requires a blood sacrifice. Now we're spoiled for choice.

Trivia

 * In "The Legend of Music of the Legend of Vox Machina", Neal Acree recounted that Sam asked him to write a heavy metal piece where Scanlan's lute playing turned into heavy metal guitar, and he thought, "All the rules are out the window." That scene took place in this episode when Scanlan used Bigby's Hand to hold the party above the rising acid.