The Bifrost.
It was both a powerful weapon of war and a swift means of transportation.
As a weapon of war, when driven at full power, it could utterly destroy an entire planet.
As a means of transportation, once activated and targeted, it could transport people or objects anywhere in the universe.
Or bring them back to Asgard from anywhere in the universe.
Thor and his companions rode across the Bifrost in a triangular formation.
Thor led the way. His face was full of excitement, and he had already made up his mind to attack Jotunheim.
Loki and Sif rode in the second row, wearing entirely different expressions.
Sif looked helpless.
She had thought that after yesterday's drunken revelry, Thor would cool down and change his mind.
But once Thor sobered up, the first thing he did was gather them to attack Jotunheim.
Loki, meanwhile, wore a secretly delighted expression.
He had thought yesterday's interruption would ruin the plan.
But Thor was single-minded as ever and had believed his nonsense about how, if they did not find the loophole, the Frost Giants might lead an army to attack Asgard next time.
They were going to Jotunheim to confront the Frost Giants and uncover the truth behind their invasion of Asgard's treasury.
Vaguely, Loki felt as though he had forgotten something.
Shortly afterward, Thor and the others reached the end of the Bifrost, where a towering figure in golden armor blocked their path, both hands resting on a sword planted in the ground.
It was Heimdall, guardian of the Bifrost.
Legend said he could see in every direction and hear everything, watching over the Nine Realms for God King Odin.
Just as Thor stepped forward to explain their purpose, Loki moved first and stopped him. "Leave it to me."
Smiling, Loki