Brave New World is now playing in theaters everywhere, and while it may be a rocky start for Marvel to kick off the year, the fourth Captain America movie does tie up some knots from prior MCU films,

Captain America: Brave New World brought Red Hulk to the MCU for the first time, with Harrison Ford taking on the role people have wanted to see for many years. However, despite the character being visually impressive, Red Hulk didn't leave fans wanting to see more.

There, adamantium is a man-made steel alloy. In the 616 timeline, however, we've just found out its origin is as alien as vibranium's, and Earth's scientists are considering it an all-new element. Red Hulk's appearance in the fourth Captain America movie brings back the quite silly Marvel science of gamma rays to the forefront of the MCU.