Isaac found himself hiding in the perimeters surrounding the castle. Still far from the walls of the castle ground, but near enough to initially scout the place.
"Let me see what we have here." He moved closer but kept his vantage point at the top of hilly land.
He did not have X-ray visions or binocular eyes, but his eyesight was good enough to spy on what was happening inside the gates. He had been Adam's leading scout during the war, and this was a piece of cake.
He climbed a tree that had thick branches and lush leaves. It would help him hide, at the same time, giving him a good view of the landscape. He immediately scanned the area that his eyes could easily reach.
Once he had a better overview of his surrounding, he could plan better before moving closer. It had been decades since he was last inside the castle. So things might have changed since then.