Under the pretence of being bank officials the men involved - Ezarra, Txabi, Iker and Luken - settle in Madrid and plan to kidnap the "Ogro" from the church where he goes to mass each morning.

However the planning has to change since Carrero Blanco becomes Spanish Prime Minister and Henry Kissinger was set to come visit him, all the security measures around him were multiplied.

Operación Ogro ("Operation Ogre") was the name given by ETA to the assassination of Luis Carrero Blanco, the then Prime Minister of Spain in 1973 and the successor of Spanish caudillo Francisco Franco.

An ETA commando group using the code name Txikia (after the nom de guerre of ETA activist Eustakio Mendizabal killed by the Guardia Civil in April 1973) rented a basement flat at Calle Claudio Coello 104, Madrid on the route over which Carrero Blanco used to go to Mass at San Francisco de Borja church.

On 20 December 1973, a 3-man ETA commando group disguised as electricians detonated the explosives by command wire as Carrero Blanco's Dodge Dart passed.