lightning in a bottle

Short definition from Wiktionary

Noun

1. 1
   That which one seeks in attempting a difficult or challenging feat.
2. 2
   A very difficult, unlikely or lucky achievement or period of success.
3. 3
   Ephemeral state or atmosphere, as at a startup company or artistic group.
4. 4
   Used other than figuratively or idiomatically: see lightning, bottle.