Barchu

The tenth Jew arrives, triggering a chemical reaction.  Faces, voices, bodies and minds set each other into motion. 

One voice calls out to the others, summoning them to join together in prayer. The nine bend and bow, responding that they have become a minyan, a quorum at prayer.  

If there are less than ten, the reaction cannot occur and there is no call.  Then each one is left alone, a solitary soul making its way toward God.