Second person, future tense… almost.
“Good evening, sir” the guard’ll say to you,
Evidently fooled by your disguise.
You’ll nod and pass, in hopes that’s right to do
And that your nodding won’t cause him surprise.
Then, once inside, you’ll doff your wig and cape
And look about for that one unbarred vent
Through which you’ll crawl, and thus make your escape,
Satisfied that none know how you went.