Or, the martial group knows to enter the Wyrwood at twilight, and that is a liminal path to the fae court.
Or, no, they don't have access to that since you need a spellcaster. Nothing wrong with that, not every class has access to every option. Nor should they. But, maybe there exist other options that bring up other resources the DM didn't consider.
The fighter may have 120 troops that serve him, a ranger might have a herd of friendly hippogryphs the know about, or the rogue contacts the alchemist inservice to the guild she runs to get the perfect poison for the occasion.