Running for Whose Life? (2006)

From publisher blurb:

The agents are sent to Pamplona, Spain, on the trail of one Serge Nixon, who has stolen the blueprints of a voice-recognition detonation system which UNITAS want back before they fall into the wrong hands. Intelligence suggests that Nixon, who originally hails from Pamplona, intends to sell the blueprints on the open market, but judging by past behavior it is unlikely that he will miss the annual Sanfermines festival — the so-called “bull run."

The agents’ first task is to locate Nixon in the middle of a very crowded and lively festival. Once they've tracked him down, the chase is on… and it’s almost time for the famous — and dangerous — bull run to begin.