This is the first drill in a series of flow passing drills. It is a good drill for the start of practice as it gradually adds complexity, number of passes, and skating requirements. Each drill requires the same formation in with a line placed at each one of the neutral zone face off dots.
On the whistle opposite lines will go at the same time as shown in the diagram. The first pass is made to the line directly in front of the player. Player 2 receives the pass and passes it right back to Player 1. Player 1 then attacks the zone for a long shot on net. Player 2 then passes to the next player in the line from which Player 1 just came from and repeats the drill.
As players attack the zone you can emphasize different types of shots, skills, or shooting angles for the goalies.