Whether his flatness is cultivated or deliberate, there's a limit to what Dirk's stoicism can withstand.

But it turns out shock is a powerful force. His head jerks back, furry eyebrows rising sharply, mouth opening wordlessly. His eyebrows snap back down before he closes it, but he still doesn't know what to say exactly. No, wait. Yes he does.

"Ten years?"

Congratulations, Shiro. You unlocked a few seconds of obvious human emotion!

Not to be confused with Dirk's actual emotional experience, which is frankly a nightmare roller coaster ride staffed by some real shady characters.