FBI Director Robert Mueller said the plot was so surreal it “reads like the pages of a Hollywood script.”

Iranian agents, he said, went to hire hitmen from Mexico’s ruthless Zeta cartel to assassinate the Saudi ambassador on U.S. soil.

Or did they really?

The indictment shows that no genuine Mexican cartel operatives were involved at all.

Instead, the alleged Iranian agent Manssor Arbabsiar ran straight into the mysterious CS-1 — a confidential informant for the Drug Enforcement Administration.

CS-1 then carefully lured Arbabsiar down the garden path — until he had allegedly paid $100,000 up front and promised $1.4 million more for killers to use guns and bombs against the target, according to the indictment.

Watching the relentless violence in Mexico, many have feared for some time that the ruthless cartels could bring their bloody mayhem north of the Rio Grande.

But taking out such a high-focus diplomatic target in the United States is the last thing that Mexican cartels want to do.

The traffickers make an estimated $30 billion every year selling cocaine, marijuana, crystal meth and heroin to American users.

Why would they want to bring heat on this lucrative industry by plunging into the cauldron of Middle Eastern politics?

The cartels are even cautious about murdering rival drug dealers on U.S. soil.

(See Mexican asylum seekers head to U.S.)

After a cell of Zetas committed a string of five homicides in Texas in 2005 and 2006, U.S. police hit back hard, rounding up Zeta operatives and dishing out mammoth prison sentences.

Since then, the cartel has been very quiet in its land of milk and honey.

A crucial question over the assassination case is who contacted who first.

Was the whole idea in fact dreamed up by American intelligence ops, who went to Arbabsiar with the proposal?

Perhaps we’ll find out by the time the Hollywood film about this is actually made.

