Riddles In The Dark EP 11 - Hard To See In The Starlight

Lord Commander Farrel exited his tent, his aide to camp stood at the ready holding the reigns of his steed. The Captain of the starlight company sat upon his horse a short way off. As Commander Farrel mounted his horse he called to the Captain. "Aldarp...ALDARP!"

Aldarp stirred and with an effort focused on the Commander. "I'm sorry sir!" He said. 

"Thats alright Aldarp its been a long night"

"Its not the night sir, its my company, they're gone"

"They deserted?!"

"No sir, thats the thing, all of their equipment is there, its as if they vanished, and the horses were taken off their ropes and the ropes tossed in the trees"

"Take me to the site!" Commander Farrel ordered.

When they arrived, it was all as Aldarp had described. Farrel ordered for men to take down the ropes and round up the horses, but first he abruptly ordered the arrest of Captain Aldarp.

Why was captain Aldarp arrested, and what happened to his company?