On Tuesday, Chris Hemsworth and Tom Hiddleston visited Lady Cilento Children's Hospital in Brisbane, Australia.
During the visit, the actors were interviewed by children for Juiced TV, a show made by the kids in hospital.
And it looked like a truly joyful experience for everyone involved.
Real-life superhero Calyn was one of the children who met Tom and Chris. Three years ago he saved his younger brother by running onto a road to push him out of harm's way. But Calyn wasn't able to get off the road in time and was hit by a four-wheel drive.
Calyn's mother, Shana, told BuzzFeed their encounter with the actors was absolutely unforgettable, and it was the first time she had seen her son smile so big.
She added that before his accident, Calyn was a big Marvel fan and even had custom Thor shoes made.