remembered his bygone services, he would have made peace once more. He
only waited till Prometheus should bow his stubborn spirit, but this
the son of Titans would not do. Haughty as rock beneath his daily
torment, believing that he suffered for the good of mankind, he endured
for years.

One secret hardened his spirit. He was sure that the empire of Zeus
must fall some day, since he knew of a danger that threatened it. For
there was a certain beautiful sea-nymph, Thetis, whom Zeus desired for
his wife. (This was before his marriage to Queen Juno.) Prometheus
alone knew that Thetis was destined to have a son who should be far
greater than his father. If she married some mortal, then, the prophecy
was not so wonderful; but if she were to marry the King of gods and
men, and her son should be greater than he, there could be no safety
for the kingdom. This knowledge Prometheus kept securely hidden; but he
ever defied Zeus, and vexed him with dark sayings about a danger that
threatened his sovereignty. No torment could wring the secret from him.
Year after year, lashed by the storms and scorched by the heat of the
sun, he hung in chains and the vulture tore his vitals, while the young
Oceanides wept at his feet, and men sorrowed over the doom of their
protector.

At last that earlier enmity between the gods and the Titans came to an
end. The banished rebels were set free from Tartarus, and they
themselves came and besought their brother, Prometheus, to hear the
terms of Zeus. For the King of gods and men had promised to pardon his
enemy, if he would only reveal this one troublous secret.

In all heaven and earth there was but one thing that marred the new
harmony,--this long struggle between Zeus and Prometheus; and the Titan