Loki: Agent of Asgard (2014 series) #1

The story opens with Loki stabbing Thor in the back. Literally. With a sword. He says "Trust me. I know what I’m doing."

Earlier, Loki was approached by the All-Mother while showering and called to a new mission. This soon sees him running up the side of Avengers Tower in his magical Seven-League Boots and hidden from view by his Vanishing Cloak. He finds Thor alone, drinking himself into a stupor on the top floor. As soon as the God of Thunder smells his treacherous brother he hurls his hammer at him knocking him from the side of the tower. As Loki plummets, he is spotted by Hawkeye and the Black Widow from a lower floor. Hawkeye fires a grappling arrow which snags the young god and they pull him into the room. There Loki is confronted by all the Avengers, including Iron Man and Captain America, who demand to know what he is up to. Loki introduces himself as a secret agent for the All-Mother and suggests that Tony Stark is still experimenting with Thor’s DNA. In the sudden tense atmosphere, Loki makes his getaway. Hawkeye fires an arrow to stop him…and hits Bruce Banner. Banner turns into the Hulk and chaos results—to put it mildly. Loki then saunters down to the computer room and erases all record of the original Loki’s misdeeds. Loki is caught there by the Avengers and Thor wants to kill him; Loki ducks behind the clumsy warrior and stabs him in the back…which is where we came in. It is revealed that Thor’s body has been corrupted by Malekith’s touch (in THOR, GOD OF THUNDER #13-17) and the magic sword Gram is used to draw the poison out and contain it in a jar. Then the Hulk punches him….

Later, Thor thanks Loki for his efforts as they share a drink. Loki naturally escapes and returns to the All-Mother and delivers the jar of lies. As his reward for a successful mission, one crime is purged from Loki’s record. Loki departs—and the All-Mother opens the jar, releasing—old evil Loki….