Walter Sykes is the main antagonist in Season 3. He was the former head of a shell company called A to Z Technologies. The name of the company, it is later revealed, was inspired by his childhood baseball team, The Aztecs. Paralyzed since childhood, he is confined to a wheelchair. In 2001, he dropped off the grid along with the millions of dollars that his company made. He was attempting to find out any information he could about the Warehouse, though it is assumed he had quite a bit already. Sykes had already started to collect artifacts that the Warehouse hadn't even heard about yet like the Berlin Wall Spray Paint Can. In "The New Guy", he ordered an assassin to collect as much information about the Warehouse as possible. The assassin killed a waiter and a banker using William Shakespeare's Lost Folio, according to his orders. Sally Stukowski, FBI agent, was present at both crime scenes when Pete and Steve arrived, and had them both removed from what she declared were 'her cases'. After the assassin failed his mission to kill three bankers, he escaped the scene and reported back to Sykes. He told him all the information he knew and was promptly suffocated by Sally, having outlived his usefulness.
Later, he has Sally bug the warehouse, which she is able to succeed in doing by stealing Vincent Van Gogh's Stormy Night from Artie and Steve, then returning it filled with nanites designed by Tyler Struhl, a young computer hacker that Sykes recruited after the incident with Judah Loew ben Belazel's Amulet. Sally reports her success to Sykes, saying "it is done". He directs Marcus Diamond to kill Sally when Sally fails in her attempt to kill Jane Lattimer and Adwin Kosan, both Regents, and to destroy the Remati Shackle. Sykes then orders Diamond to dispose of Lok Archer's body and to continue Sally's efforts to cultivate Steve Jinks as an ally.
In "Shadows", it is revealed that Walter Sykes was a disabled youth confined to a wheelchair who recovered the use of his limbs through his use of Collodi's Bracelet; however, the artifact had a negative side effect, it "planted a seed of darkness" within the wearer, and after the bracelet was taken away from him he was confined once more to a wheelchair and now desires revenge.
In "Emily Lake", Steve Jinks is revealed as the latest henchman of Sykes, and he and Marcus are sent by their boss to acquire the two bifurcated bits of H.G. Wells, her body, which is now teaching English in a high school with an American persona, and her mind, which is currently stored in the Janus Coin. Tyler Struhl, who is clearly terrified of his boss, is collating data hacked from the Warehouse's systems to provide the intel for Sykes' endgame, although what that might entail no-one but Sykes, and possibly Marcus, knows. Sykes acquires the two "elements" of Helena and, in keeping with his pattern, has Marcus eliminate Steve, whose body is found by the agent trio of Claudia, Pete and Myka, who are following clues which Steve, who was always Jane Lattimer's mole, left to help them anticipate and stop Sykes.
In "Stand", Sykes is the target of revenge for the agents almost as much as he seeks to punish all connected with the warehouse for his own condition and suffering. Claudia, in particular, seems willing to cross any line to exact payment for Steve's death. Sykes has brought Helena, now reintegrated, to Hong Kong, and the final moves are clearly at hand. Helena is revolted by him, but Sykes uses Cecil B. DeMille's Riding Crop to give him control over her body. Sykes has discovered a literal backdoor into the Warehouse via the Regents' Sanctum in Hong Kong, and, after sacrificing Tyler and endangering Myka, forces Helena to assist him by opening the portal into the Warehouse. With Pete under the crop's sway, he reacquires Collodi's Bracelet and after a brief physical skirmish with the agents and Jane, attempts to flee with his prize. Pete deactivates the portal as he is passing back through to Hong Kong, trapping Sykes within the energy field which rapidly dissipates, causing his body to crumble to dust. Sykes, however, has left a parting gift - an "artifact nuclear device", as Artie puts it, which employs the pent-up destructive powers of the Luftwaffe contained in a piece of masonry from the House of Commons in London to annihilate the entirety of the Warehouse and its contents, save for Artie, Pete and Myka, who are preserved by Helena's final noble act of self-sacrifice.
In "A New Hope", Artie travels back to the moment when he had saved Helena and Myka in order to diffuse the nuclear device, which was revealed to rely on Sykes's anger and hatred to continue it's countdown. In order to deactivate the device, the trio finds Pete and keeps him from deactivating the portal before convincing him to bring Sykes back instead. Upon his return, Sykes was covered in M.K. "Mahatma" Gandhi's Dhoti and was filled with "peace". The artifact negated the side-effects of Collodi's Bracelet which diffused the nuclear bomb, however Sykes dies shortly after saying he was sorry.
In "Personal Effects", it was discovered what Walter Sykes did with his collection of artifacts. Apparently, Sykes' plan was that he'd have Marcus Diamond transport all of the artifacts he had collected to an ordinary looking house in a town that was a 4 hour drive from the Warehouse called Devils Lake, North Dakota. Sykes bought the house under the name Enrico Mazzanti and he made sure to make it look like a normal house, so after he destroyed the Warehouse he could lay low there for a while like it was a safe house. Interestingly, Enrico Mazzanti was the original illustrator for Carlo Collodi's The Adventures of Pinocchio which only proved how obsessed Sykes was with Carlo Collodi's Bracelet. However, Sykes' plan failed and for a while his collection of artifacts just collected dust in the basement. It wasn't until the cleaning lady Sykes hired accidentally activated one of Sykes' artifacts, the Boa Vista Plantation Token, that the Warehouse agents discovered Sykes' safe house. Myka was able to retrieve the token, but someone else had already stolen all of the other artifacts. It was discovered that a local man had stolen them, thinking they were just antiques, and sold them to the local pawn shop. Before the team could get there the pawn shop had already been destroyed by Catherine O'Leary's Cow Bell. Four of Sykes's artifacts were there, but six had already been sold. Among them were Bobby Jones' Golf Clubs, Richard E. Byrd's Smoking Pipe, Napoleon Bonaparte's Violin, John A. Macready's Sunglasses, and Maurice Vermersch's Waffle Iron. After retrieving the last of Sykes' artifacts it was believed that the story of Walter Sykes was finally over.
He was the greatest enemy Warehouse 13 ever faced.
- Sally Stukowski (Deceased)
- Marcus Diamond (Deceased)
- Tyler Struhl (Deceased)
- Unnamed Assassin (The New Guy) (Deceased)
- James Aquino (Deceased)
- Steve Jinks (Alive)
Known artifacts collected by Walter Sykes (these were artifacts that Walter Sykes collected and either used or intended to use against the Warehouse)
- Berlin Wall Spray Paint
- Black Bart's Cannon
- Boa Vista Plantation Token
- Bobby Jones' Golf Clubs
- Collodi's Bracelet
- Catherine O'Leary's Cow Bell
- Cecil B. DeMille's Riding Crop
- Clothing Iron
- Doorknob from the Triangle Shirtwaist Factory
- House of Commons Masonry
- Johann Maelzel's Metronome
- John A. Macready's Sunglasses
- Maurice Vermersch's Waffle Iron
- Napoleon Bonaparte's Violin
- Richard E. Byrd's Smoking Pipe
- Vincent Van Gogh's Stormy Night
- William Shakespeare's Lost Folio