
He's flying kites (more clearly, in the original), which they used to do together. His kite string has been cut by one of the Greek goddesses, the Fates, who decide these things:
Atropos is is the eldest of three sisters who determine each mortal's life span. She cuts the thread of life, when it is time for a mortal to die.
Her sister Clotho spins the thread of life.
Her other sister, Lachesis, sets the length of the thread.
Jim would have turned 52 this week.
But Atropos's name means "without turn."