The Serenity is headed for the planet Ariel, one of the core worlds, and a major Alliance stronghold, because Inara must undergo her annual medical examination as required by the Companion Guild law. Everybody’s sitting in the dining room aboard the ship talking about what they might be able to do on this advanced, wealthy world--until Mal clamps down on their plans by ordering everybody--except Inara--to remain aboard ship the entire time they’re in port. This peaceful gathering is abruptly shattered when River inexplicably stabs Jayne with a knife. The wound is superficial, but Jayne’s reaction is anything but--he wants nothing less than to leave Simon and River behind on Ariel. While Mal shoots that idea down, he’s not completely unsympathetic to Jayne’s concerns about River, whom he orders confined to her cabin. Even Simon acknowledges that his sister’s erratic behavior is only getting worse, not better.

After they land on Ariel, and Inara leaves for her check-up, Simon approaches Mal and the others with a special proposal: he wants them to smuggle him and River into one of the hospitals in Ariel City, where Simon can use the modern scanning technology to better examine River’s brain. As payment for this smuggling, Simon gives them a specific list of drugs for them to steal from the hospital pharmacy, drugs which would bring a major payday on the black market on the outer worlds. Wash and Kaylee work on transforming an old junked transport into an ambulance, while Mal, Zoë and Jayne--who will pose as paramedics--struggle with learning the proper medical jargon that will get them through the front gate. It’s a foolproof plan, and of course everything gets shot to hell once Jayne plans his own little payday.

Ariel is essentially a heist story, and it’s a gripping, edge of your seat episode that’s a lot of fun. The scenes detailing the crew’s setting up the heist are fascinating to watch, as are the frenetic sequence of events that lead up to the plan going awry with the arrival of the mysterious and deadly duo of investigators who wear blue gloves and can kill with a device that causes people to bleed from every orifice. River has been chanting a chilling little nursery rhyme about them--"two by two; hands of blue"--for the past few episodes, and after finally seeing these men in action, they more than live up to the steady build up that the Firefly writers gave them. And as if this wasn’t enough, Ariel still has a shocking twist at the very end that will blow your socks off. With its intricate writing and elaborate setting up of future plot points, Ariel is one of the episodes that really makes me wish Firefly hadn’t been cancelled.