Irony abounds when Crichton, while getting a shuttle piloting lesson from Aeryn, collides with the Flax, an invisible trap set by pirates who return periodically to take they value and melt down the rest. Trapped by the Flax, they can't see beyond it or receive transmissions, although they are able to broadcast a call for help to Moya, where fortunately the rest of the crew have encountered someone who is familiar with the Flax. The visitor pleges goodwill and promises to help them deal with the Flax, for a share of any take that can be had along the way.
The Flax itself is spectacularly rendered. Some questions about the supporting pseudoscience come to mind, such as how ships caught in the Flax can send but not receive transmissions and how ships can become caught in it and still be safe to dock with? But these kinds of practical considerations get swept aside by the excellent effects that give the Flax an evocative, dramatic presence. Sure there are glitches in the descriptions of the operation of the Flax, but it is clearly there trapping ships, so disbelief is suspended and the drama continues to build.
Repeatedly Aeryn and Crichton attempt to free the shuttle from the grip of the Flax, but succeed only in becoming more solidly trapped and cause problems for themselves inside the shuttle as their escape attempts cause violently turbulent motions. Unable to free the shuttle or to receive any transmissions from outside they become increasingly despirate to find a way to break free.
Having received the call for assistance from the trapped shuttle, D'Argo accompanies the Flax-savvy guest star on a flight to the Flax. Along the way they discover a Luxan ship trapped in the Flax in a place that indicates it is next to be melted down. Thinking that there might be maps and possibly even something of value remaining on board they head out towards it only to turn back when they decide that they trapped shuttle might be in immediate danger.