Stargate Atlantis/Recap/S04 E16 Trio

McKay, Carter and Keller get trapped underground. Hilarity Ensues.

Tropes:

 * Cross Referenced Titles: "Duet" was an episode about two people trapped in a small life-threatening space (McKay); "Trio" is an episode about three people trapped in a small life-threatening space (a disused mine).
 * Digging Yourself Deeper: McKay comments that Carter has a "perfect body" - and then realizes this might be interpreted as an insult by Keller and begins to ramble ever more awkwardly until Sam finally stops him.
 * I Have Boobs - You Must Obey!: averted (but discussed) when McKay tries to convince Carter to show the kids her boobs in order to enlist their help.
 * Locked in a Freezer
 * MacGyvering: In spades, by everyone. McKay builds a cannon.
 * Official Couple: A deleted scene from this episode finally makes Sam/Jack canon.
 * Take Off Your Clothes: McKay suggests this, in order to make a rope. Keller starts to strip...but then Carter finds some rope (and McKay is visibly disappointed).