Wormhole exploration is perhaps the key feature that came to EVE Online with the Apocrypha expansion. Its 'true exploration' of thousands of uncharted solar systems can bring great rewards but also entails equally great risks. The Sleepers are the strongest NPCs that players can face in the game's setting of New Eden, adding to the challenge of taking them on is the fact that you may be hunted down by players at the same time. The delayed local channel in wormhole space ("w-space") means you won't know if you're really alone in the uncharted solar system until you find yourself being targeted and fired upon by a roving gang of hostiles.
Wormholes can also have tactical environments which affect how well your ship operates in that solar system, sometimes imposing penalties. Then factor in that wormholes are inherently unstable and can collapse once enough ships have passed through, and you've got a fair amount of unpredictability injected into your gameplay. Wormhole collapses have led to a number of EVE's capsuleers being stranded in unknown regions and unable to find a way back into known space ("k-space"), much less navigate their way home again. That's where "Wormhole Rescue Service" and its founder Astro Glyde can help.