He stands in the center of his father's Pattern.
Last appearance of the Hall of Mirrors has suggested that he should get very far away from both Amber and The Courts, and Ghostwheel has managed to talk him into exploring the limits of Pattern's ability to transport people.
With Pattern of Amber and Logrus of Chaos both still rather cross with him, there's really only one option for that.
So, he stands in the center of his father's Pattern.
Rinaldo-the-pattern-ghost and the glowing disk of Ghostwheel's presence were both there, watching him depart.
He's not exactly clear on how he's planning to return, so he's geared for trouble - all Trumps he could possibly need, and a some blanks, a dozen spells using Cowrin's Pattern as the scaffold (Sigil of Logrus does seem to obey him for simple magic, but he isn't going to rely on it continuing to behave), a good sword from The Courts, Frakir around his wrist, a pocketful of blue crystals, and various supplies.
Unfortunately, taking the spikard unknown distance away from its ties to shadow is probably not safe, so there goes his source of unlimited magic.
"Well, here it goes." he says, and then concentrates on his destination.
Take me somewhere far, where no-one could have gone before
"Uh-huh. Let's say I'm in favor of closing horrible rifts and stopping demons. Any chance at getting to help the locals as an independent contractor?"
"Then as you do not seem in imminent danger of dying, I will go do so." Solas rises to depart. Merlin may notice that he's rather short, in addition to the pointed ears, only slightly over five feet tall
It doesn't particularly register. Many shadows, many kinds of people.
After Solas had left, Merlin carefully calls the image of the Pattern, putting barely any power into it, and checks his spells. Huh. Sleep spell, simple shield, and paralysis are gone, but the rest don't show visible signs of decay... So, he probably got into a fight, but it hasn't been more than a few days from his departure.
He quickly scans the room with magical sight, not really expceting to find anything, and also checks his stuff to find most of it gone, including the Trumps. Well, he'll try to find them later. He dismisses the image.