Spock was forced into brief and unfamiliar hesitation. Data, but not as he remembered him. Younger, albeit with the experience of having met him; not a Captain yet, no simulated gray to his hair. They had not met again yet. He made an unusual - but reasonable - guess.

"Commander Data."

And turns toward him entirely, head inclining in greeting. "I am in respect, deeply grateful to see you. Are you here alone, as I am?"