Jason, an undiagnosed patient carrying two years of failed medicine and mounting debt, walks into Princeton-Plainsboro with a gun and takes clinic hostages, demanding House solve what sixteen doctors couldn't. House works the differential by phone with his team while SWAT waits outside, using Cuddy's office walls as a whiteboard — and Thirteen volunteers as the human test subject for every drug, framing the risk as rational given her Huntington's diagnosis. The diagnosis turns on a kidney discrepancy: Thirteen's fail, Jason's don't, which points to a long-term antacid incidentally protecting him and ultimately to melioidosis contracted in Florida.

The episode uses the hostage structure to pressure two character arcs simultaneously. House's willingness to hand a gunman back his weapon rather than admit defeat gets named directly, and Thirtee ...