Allen Clegg is an American agent, appearing in 5 episodes and is often an antagonist against Murdoch. He first appeared in "Confederate Treasure" in season four. The next episode Allen appeared in was "War on Terror" in season 5, followed by the premiere of Season 6: "Murdoch Air", in season 7: The Spy Who Came Up to the Cold, and season 9: 24 Hours Til Doomsday.
Confederate Treasure
Initially posing as a reporter named Carson Turner for the Toronto Gazette, Clegg approached Det. Murdoch under a fake alias for a comment on the remains of Mortimer Shanly, the first Minister of Militia Defense. However, he was more interested in knowing if perhaps he had found a letter from Sir John A. MacDonald on the body. When Murdoch declined to confirm or deny any claims to the case, Clegg left. Later, Murdoch is approached by Terrence Meyers, warning him that if he is approached by Clegg, to not say a word to him. Murdoch responds with telling him that he had already met him, albeit, under a fake alias. Meyers then informs Murdoch that his real name is "Allen Clegg", and that he is an American government agent. Later on, Murdoch brings in Clegg for questioning following Burt Jacobsen's murder, with Jacobsen's wife being witness to Clegg rummaging to his belongings. Clegg drops all pretenses and states that Jacobsen was already dead when he arrived and he was searching for information on the Elvira May, a ship that was believed to be transporting millions in value of gold bars sent from the Canadian government to support the Confederates during the American Civil War. Murdoch became skeptical of Clegg's claims, insisting that Canada was neutral during the conflict, but Clegg stated that his government has its own agenda.
Clegg later caught a fishing boat carrying Murdoch, Meyers, Brackenreid and Crabtree scavenging the Elvira May's cargo. Clegg was expecting to find gold bars, only to find bricks instead, as a series of betrayals during the gold transfer resulted in bricks being put in their place. Clegg was then forced to let the Canadians go.
War On Terror
Clegg returns, having infiltrated the Toronto anarchist chapter when Emma Goldman arrives in the city, at the same time Murdoch and Meyers did too. He confirmed that Emma was not responsible for the bombing of Peter Milne's shop, which everyone assumes the anarchists committed, though he couldn't speak for the others. Meyers then inquired why he was in Canada without the authorization of the local government. Clegg said he didn't need permission, but after being reminded by Murdoch not to blow their cover, stated that the British Foreign Office, whose authority outranks the Canadian government, granted him permission.
Clegg influenced the young anarchist Pierce into committing a bombing in the square where Emma had given a speech, claiming it would impress her, though nobody got hurt. Emam deplored Pierce's actions, stating that it would not help their cause. Clegg, on the other hand, told Pierce that he did the right thing and that Emma was just being emotional.
Murdoch's cover was soon blown by Albert Wallace, a communist he had previously interviewed, forcing him to quickly declare Pierce under arrest. Clegg convinced Emma to let Murdoch go, stating that she was too important to the cause to be imprisoned.
After Constable George Crabtree determined that the bombing was caused by Milne's own landlord, Meyers personally escorted Clegg to the train station so he could accompany Emma back to the States. But before departing, they reveal that President McKinley's intended visit to Canada had been canceled by the State Department. Clegg promised that America will protect its own. Murdoch retorted that he felt that the Americans make their own problems, to which Clegg claimed was for God's country.
Murdoch Air
Clegg, acting under the alias Gleason, funds inventor James Pendrick to build his flying machine known as the Pendrick Arrow. But when the Canadian agents steal the aircraft in the name of national security, Clegg, in turn, stole it from them. But as he did not know how to make the Arrow turn, he kidnapped Pendrick, dislocating his recovering left shoulder to force him to cooperate, so he could learn how his flying machine works. When Murdoch learns of Clegg's involvement, he rescued Pendrick and the two made their way back to Canada via air. Clegg attempted to shoot them down but was unsuccessful.
24 Hours Til Doomsday
Clegg returns as the American ambassador to Canada. He is informed by the Prime Minister of Canada, Sir Wilfrid Laurier, that a rouge Canadian federal minister has threatened to fire a rocket projectile from Ontario to New York delivering some 200 tons of TNT in less than 24 hours. The Prime Minister wanted to inform the American government while Detective William Murdoch, the constabulary, and Canadian agent Terrence Meyers are working to find the rouge minister. Clegg appreciates the information, however, he ensures that if they failed and indeed lives are lost, the state of war will exist between the United States and Canada.
Following an investigation, it was revealed that Clegg actually met with the rouge minister to discuss a top secret defence plan involving a Canadian inventor James Pendrick. Unbeknownst to the inventor, the plan calls for mutually assured destruction if Canada and the United States were to be at war. However, Clegg in fact wanted to use the plan to incite war between the United States and Canada. To tie up loose ends, he also killed the rouge minister. At the end, he was arrested following the revocation of his diplomatic immunity. When asked by Meyers about his motivation, he answered that he did it for the safety of his country.