James heard Sirius, and took that as a signal that it was safe. That was the command to wipe the map clean, and Sirius wouldn't do that if anyone else was on their way up here. He had to know that they were alone. He took off the cloak.
"Right, here's the plan," he said. "We're going to send Moony an owl. And follow it." He had a small bit of torn, blank paper in his hand, and he tied it quickly to the owl's leg. If anyone else found the owl, it would look like someone had torn off the letter that had been attached. He glanced at Sirius, still holding on to the owl's leg so that it wouldn't take off. It pecked at his hand, but he didn't give a fuck. "Ready?"