Plot, intrigue, machination, conspiracy, cabal are comparable when they mean a secret plan devised to entrap or ensnare others.
Plot implies careful planning of details and usually an intent to accomplish an evil, mischievous, or treacherous end; the action may involve one or more devisers and a person, a group, a class, or a people as the victim.
Intrigue implies more complicated scheming or maneuvering than plot and often the use of petty underhand methods in an atmosphere of duplicity; it more often implies an attempt to gain one’s own ends through clandestine means (as in politics, in business, or in love) than (as plot frequently implies) an attempt to destroy, to betray, or to usurp power.
Machination, usually in the plural, imputes hostility or treachery to the makers; often, also, it suggests craftiness in devising or contriving annoyances, injuries, or evils. If these ideas are to be connoted, it may be applied to a plot, an intrigue, or any of the secret plans named by the words in this group.
Conspiracy differs from plot chiefly in implying a combination of persons or groups as the devisers and agents and in being applied chiefly to a plot that involves treason or great treachery.
In technical legal use the word implies the doing of an unlawful act or the use of unlawful means in accomplishing a lawful end.
Cabal applies usually to an intrigue in which a group combines to accomplish some end favorable to it but injurious or disastrous to the person or group, often, specifically, the government, affected.