Theo nodded, taking a deep breath in preparation. 'I am ready,' he said simply, waiting for Severus to be the same.
The challenges thrown at him now was, he knew, harder than before, but then he'd become a lot better than he'd been. Severus was a skilful teacher and he was a talented student. He could not yet break into someone's mind without them sensing him there, but he could break through most of the normal blocks, though he was still no match for a strong Occlumens. At least not a prepared one.
He would be though, he was determined to be.
Raising his wand, he thought rather than said the spell, pushing into Severus' mind.