What is the main conflict in Perdido Street Station by China Mieville?

A Sambo-like obsessive compulsive scientist named Isaac pursues crisis energy, a force he learns about by observing the water sculptures of an inscrutable race of Wyrmen. His lover is Lin, a part human-part grasshopper artist. Together, they feel like outcasts in an already-freakish world where they must hide their affair for fear of public censure. The author begs but does not answer the question of how this menagerie of hybrids and mutants came into existence in the first place. There seems to be no time to address such fundamentals when there is a huge, pulsating pupa in Isaac's laboratory and a depressed garuda who will pay a handsome sum of gold to be outfitted with a reasonable facsimile of the wings he never had. With this all-too-human motive, Isaac ransacks every science book he can find in search of the best way to power these avian prostheses. He settles on crisis energy.