The mystery unfolded on December 9 at the Media Luna park in Pamplona. The Civil Guard had placed an envelope in a nook in the city wall, the place where the then-president of the Caja Navarra savings bank, José Antonio Asiain, had been told to leave 25,000 euros in exchange for information being kept under wraps that his bank had done business with his son's legal firm.
To the surprise of the watching officers, the man who arrived to collect it was Popular Party (PP) deputy Santiago Cervera, who was arrested.
Cervera said he had been the victim of a trap, telling agents he had come to the spot because he had received an email on November 29 saying that he would find information relating to Caja Navarra there.
But five months later, as the investigation phase of the case continues, Cervera remains the only suspect in the case. He has been forced to give up his seat in Congress and his party membership card, while the fallout from his arrest is threatening to break the unstable political balance in the Navarre region, where the conservative Navarrese People's Union (UPN) rules in a minority government.
Cervera made enemies within the UPN and the PP since he switched to the latter party
The question is, who are the enemies that Cervera has who would be so bold to orchestrate such a plot? The email sent to Asiain telling him where to leave the money three days prior to Cervera's arrest mentioned the Kontuz collective as a possible route through which the information he was being blackmailed with might be passed on.
Associated with the abertzale left group of Basque nationalists, Kontuz has been one of the most active groups in issuing warnings about irregularities at Caja Navarra. Its complaint against the bank, made just after Cervera's arrest, has led to a number of high-profile figures in Navarre politics appearing on the stand, including former UPN regional premier Miguel Sanz and Pamplona Mayor Enrique Maya. The scandal also threatens to taint incumbent regional premier Yolanda Barcina.
But, despite their ideological differences, Kontuz has always defended Cervera as the victim of a trap and praises the former deputy's work in criticizing the bank.
Others identified as having an interest in silencing the ex-deputy include former chiefs at Caja Navarra, but the fallout from the case has hardly been beneficial to them. Asiain's role as president of the savings bank ended on January 3, when Barcina's government decided to dissolve its agencies and name an administrator for its foundation, the only part of it not in the hands of new owner Caixabank.
Cervera has also made numerous enemies within the UPN and the PP since he switched to the latter party in 2008. And it is hard to deny that Cervera has also been his own worst enemy in this case. His curiosity and eagerness to denounce irregularities at Caja Navarra are what led him to such an unconventional appointment. His declaration before the judge last Friday leaves many matters still to be resolved. Was something else left in the nook in the intervening seven days between the email received by Cervera and the one received by Asiain? Did anyone else know about the email?
All those involved in the case say the investigation will reveal the mystery hidden in the nook. What they don't know is when.