Spring Hercules

Can anyone help me explain these two references?

In "The Scarlet Ibis" - "I already admitted defeat, but my pride would not let me. The excitement of our program had been missing for weeks, but we still rest tired. It was too late to turn back, because the two had wandered too far into a thread of confidence and not let the crumbs behind. "The allusion is" had no crumbs or Walden Henry David Thoreau, commenting on how their neighbors have worked hard - "The Twelve Labors of Hercules were trifling in comparison with those who have made my neighbors because they were twelve, and had a final, but I could see that these men had killed or captured any monster or finished work. They have no friend Iolaus burn with a hot iron at the root of the head of the hydra, but as soon as one head is crushed, two arise. "With reference to last sentence. PLEASE HELP

"If crumbs" It's like Hansel and Gretel .... story for children who were lost in the woods and left the crumbs to be able to find their way back, it's too late to back because there is no way to find your way .... no crumbs to follow ... They had so many expectations and hopes and it is difficult find where it all began