Loki: Agent of Asgard #1 (2014)

In the present, Loki stabs Thor with a sword. Some hours before, in an apartment, Loki's attempt at showering is interrupted by the appearance of the All-Mother, who have an assignment for him. This leads to Loki running up the side of Avengers Tower, via some Seven-League Boots, and using a vanishing cloak to make himself invisible to the Avengers. Inside, Thor is in an uncharacteristically aggressive mood, demanding mead from Jarvis. He notices Loki peering in through the window, and attacks. Loki's fall catches the attention of Hawkeye and Black Widow, and he is saved from plummeting to his death by a grappling arrow. This does however leave Loki surrounded by the Avengers. On questioning from Thor, Loki openly tells the truth: that he is working on behalf of the All-Mother, before distracting Thor by reminding him about the time Tony Stark cloned him. This enrages Thor, allowing Loki to slip past. Hawkeye's attempts to stop him fail, due to some magical misdirection from Loki causing the archer's arrow to wind up in Bruce Banner. Using the distraction, Loki makes his way to the Avengers Database, and uses it to find all the information the Avengers, S.H.I.E.L.D., and anyone else, may have on him, before promptly deleting it all, since those stories contained a metaphysical weight that would pull Loki back towards villainy, something Loki wishes to avoid. However, in the time it takes to do this, the Avengers catch up to him. Thor advocates killing Loki, and tries to do that. In that instant, Mjolnir becomes impossible for him to carry, allowing Loki to slip around Thor, and stab him, causing strange energies to pour out of Thor's body. In a flashback, it is revealed why Loki has stabbed Thor; after his most recent encounter with Malekith the Accursed, some manner of corruption has entered him, causing Thor to become increasingly violent, arrogant and belligerent. This is why Loki retrieved Gram, the sword of Sigurd, which forces those it injures to suffer the truth. It works, freeing Thor from the contamination, which is promptly sealed in a special jar Loki had brought along, though his celebration is cut short when the Hulk knocks him out. A short time later, in a cell, Thor and Loki talk. The thunder god ruminates of his former history of arrogance, and whether he has in fact changed since those days. Loki reassures him, and the two brothers share a drink before Loki's inevitable escape. Afterward, Loki presents the sealed corruption to the All-Mother, who reiterate his terms of service; for every mission accomplished, one misdeed of Loki's will be removed from Asgard's books. Loki tries to warn the All-Mother, and Frigga in particular, against opening the jar, but is instead commanded to leave. As he does, the jar is opened, and the corruption takes a familiar shape... that of Loki. An older, evil Loki. One who wants to talk about the future.