mare's nest

Etymology
Alteration of earlier, from the fanciful and unlikely notion that horses make nests.

Noun

 * 1) A great discovery which turns out to be illusory; a hoax.
 * 2) * c. 1620,, Bonduca, V.2:
 * Why dost thou laugh? What Mares nest hast thou found?
 * 1) A confused or complicated situation; a muddle.