There's a dark side to Jose Mourinho, brilliantly illustrated in a book of the same name by journalist Diego Torres of the serious Spanish broadsheet El Pais. Recently translated into English, it is recommended sunbed reading for the Costas this summer.
Clearly sourced from the inside, well-informed Torres provides a variously fascinating, hilarious and disturbing insight on Mourinho's Real Madrid reign; the wild extremes ranging from paranoia to fury at perceived enemies within and without and even conspiring to lose to bitter rivals Barcelona in such a way as to blame the referee.
Small wonder by the time he returned to Chelsea, the Special One was considered to have lost the plot, evidenced by more irrational rantings against referees and the system in recent weeks.
Pouting and posturing, he is as unsavoury to some as he is charismatic to others.
And yet, as his outsmarting of his former disciple Brendan Rodgers at Liverpool proved, there is no greater guarantor of results in world football today than Mourinho, nor master of mind games. Brendan knew he was being played and still had no answer.
Normally cool under fire, Brendan even allowed himself to be goaded into sniffily deriding Mourinho's tactics.
Hard to combat Chelsea may have been, but that was Brendan's job and he knew it was coming. Had Mourinho meekly run up a white flag with an eye to Atletico on Wednesday, he'd have been even more roundly and deservedly condemned.
Love him or loathe him, Mourinho's methods bear fruit while Brendan's remain on the vine. In that respect, when it comes to the dark arts of winning, the apprentice still has much to learn from the sorcerer.