A victory by the team seems 'within the realm of possibility'. [=a victory seems possible]
It's not 'beyond the realm of possibility' [=it's not impossible] that he will return.
new discoveries in the 'realm' of medicine
(..) Night gathers and now my watch begins... Not that bit, the bit at the end. I'm the sword in the darkness, the watcher on the walls, the shield that guards the realm of men. - I pledge my life... - Okay, that's enough. Shield that guards the realm of men. That's what you swore to be. (..)2015 TvShow: Game of Thrones Title: High Sparrow Season: 5 Episode 3