Langtry is tall and broad-shouldered, and has cold blue eyes; he wears his hair long, and has a long silver beard. His hair and beard is long, all snowy white with threads of silver, and perfectly groomed. His eyes are winter sky blue and alert, his features long, solemn, and noble.
Ebenezar McCoy comments about him that: “as usual, he's half right half wrong, and all gutless.” However, both Harry Dresden and Carlos Ramirez have answered that "You don't get to be Merlin by collecting bottle caps."
In Turn Coat, he talks mind-to-mind to the essembly at large, directing hundreds present what to do and not do during the Mistfiend attack. And, he tells Harry Dresden to capture Samuel Peabody who is escaping. He wears a blue robe and a silver circlet about his brow, and his staff is of elegant pure white wood, completely free of any marking.
In Changes, when he and Harry meet in the Warden's Worry Room the Merlin of the White Council was dressed in simple white robes. He also wore a gunslinger's type belt of white leather hung at his hips. It looked something like the tactical gear made for Special Forces operators. Multiple potions vials rides in individual leather cases and the leather-wrapped handle of an anemic rod or a stubby wand pokes out of his holster. Several of the pouches were fastened closed, and looked as though they would contain bits and pieces of the standard wizard gear. He also bore a long, white staff, a simple wooden pole made of an unfamiliar wood.
In the seriesEdit
- Main article: Summer Knight (novel)
During the conclave, Arthur Langtry tried to railroad one of his cronies onto the Senior Council in Pietrovich’s seat sans discussion so that he could control the vote. Martha Liberty called for general debate allowing the opportunity for Ebenezar McCoy to get the position. Langtry, Aleron LaFortier, and Ancient Mai tried to get Harry stripped of his Wizard status on the White Council which would allow them to turn Harry over to the Reds who would murder him. Later on, Morgan shows up at Harry’s apartment and tries to goad him into attacking; Just in time, Harry figures out that another wizard is waiting outside to witness Harry attacking an unarmed Warden unprovoked, and realizes that the Merlin had set up the entire thing to try to get rid of him.
- Main article: Dead Beat
In Dead Beat, Anastasia Luccio updated Harry on The War. Luccio said that Langtry went out into the field with the Senior Council, convinced to do so by Ebenezar McCoy. The Red Court attacked them on the Ways in Sidhe territory as they retreated with a great many wounded. The Reds called up Outsiders and Demons. Ebenezar McCoy and Martha Liberty came to their aid buying time for Langtry and the Gatekeeper to hold off an entire army of Red Court vampires and demons with a Ward while the Wardens escaped with the wounded.
- Main article: Proven Guilty
In Proven Guilty, the Merlin is present along with the Wardens and Harry at the execution of a Korean boy who had violated the Laws of Magic and caused horrific damage to his family. After the boy is killed, Langtry and Harry speak, and Harry talks about his sorrow over the execution. The Merlin firmly tells him that the boy was incapable of rehabilitation and there was no other way. He softens slightly at the end of the conversation, telling Harry that it wasn't easy, but the Laws of Magic had to be obeyed.
At the end of the novel the Merlin reappears for the trial of Molly Carpenter. With most of the Senior Council on assignment, Langtry holds 6 of 7 votes, with the Gatekeeper being the only odd vote. Harry calls upon the sympathy of the witnesses, showing them Molly’s face and talking about learning from mistakes. He wins the room, but as soon as he looks at the Merlin he realizes his mistake; he had undermined and insulted the Merlin, using the trial as a direct challenge. The Merlin responded by acknowledging Molly’s age, but declared he was unwilling to take chances with the war against the Red Court going so badly and ordered her immediate execution.
Before the sentence could be carried out, the rest of the Senior Council arrives with Michael Carpenter, who had just saved all their lives and the lives of dozens of younger wizards in battle. Harry quietly points out to the Merlin that as Michael had saved plenty of their lives, they could save his daughter. He also adds that there’s no downside; if Harry is right, they get a talented wizard, and if he's wrong, they can still execute Molly. Langtry agrees, but adds a threat by noting that if Molly is killed, Harry will die too.
- Main article: Turn Coat
In Turn Coat, while Listening, Harry learns that Langtry is the one pushing Joseph Listens-to-Wind to perform the ritual to find the real killer. Samuel Peabody takes Listens-to-Wind away for signatures. Harry approaches him, offers help in exchange for copies of Morgan's file. Langtry's condition is to find the traitor, the real killer, not simply prove Donald Morgan's innocence.
At the end of novel, Aleron LaFortier's supporters claim Merlin ignored their safety and was negligent with security. Langtry decided to allow rumors saying that Morgan and Peabody conspired feeling that it was better to appear as having acted with deadly strength and power. This also allows those behind Peabody to know that the Council killed an innocent man and one of their largest military assets. The Merlin had asked Klaus Schneider to decline the Senior Council seat. The seat went to Gregori Cristos who threatened that he and all of his allies would secede if he didn’t get the seat.
- Main article: Changes
In Changes, Harry sees the Merlin in the Warden's Worry Room. Langtry doesn’t buy into Gregori Cristos's currying up to Arianna Ortega for peace with the Red Court. But a lot of wizards on the Council do. So, Langtry is putting up a pretense with his own plot in the works and demands that Harry play along. He said that one child is not worth the lives of many hundreds of children. Harry disagrees saying that Langtry has it backwards—no life is worth less than that. Langtry subtly threatens Molly with his eyes, Harry leaves with Molly keeping himself between her and Langtry.