In a word: fantastic! This was a fun story aimed at younger readers but absolutely worth it for any age. This graphic novel features a much younger Thor and Loki, with lots of mischief but no malice. The artwork perfectly suits the tone, with the cover art being carried through inside as well. (I have Gurihiru figures of the brothers, adorable!)
Loki is prone to daring Thor into misadventure and Thor is prone to accept - landing both in trouble. After stealing a magic horn from Odin's vault, Thor hands it to Loki who promptly blows it, summoning... the Midgard Serpent's little sister?! They cause quite a mess, but Loki lifted something else in the vault that will transport them somewhere unexpected..
Not only is this light-hearted, it's extremely funny. I really hope we get more adventures!!