Ailing

inscrutable \in-SKROO-tuh-buhl\, adjective:
Difficult to fathom or understand; difficult to be explained or accounted for satisfactorily; obscure; incomprehensible; impenetrable. 

US Secretary of State Madeleine Albright recalled the inscrutable comment of a French diplomat about the interaction of the various European organisations: "It will work in practice, yes. But will it work in theory?"
-- Jonathan Fenby, France on the Brink

There is nothing mysterious to a seaman unless it be the sea itself, which is the mistress of his existence and as inscrutable as Destiny.
-- Joseph Conrad, The Heart of Darkness

He delighted in keeping people guessing. His thought processes were eclectic, inscrutable and unpredictable.
-- "Martin Mogridge", Times (London), March 17, 2000

A page of John Lennon's enigmatic lyrics for "I Am [the] Walrus," one of the Beatles' most inscrutable songs, was sold for £78,500 at auction in London yesterday.
-- John Shaw, "Lennon lyric sells for £78,500", Times (London), October 1, 1999

Inscrutable is from Late Latin inscrutabilis, from Latin in-, "not" + Late Latin scrutabilis, "searchable," from Latin scrutari, "to search through, to examine thoroughly (as if rummaging the trash or a heap of discarded garments)," from scruta, "trash, rags." The noun form is inscrutability. It is related to scrutiny, "careful examination."