Standard II - The Citadel is the second installment of the series featuring MI6 agent William Shanahan and undercover operative Jack Gawain. Once again Great Britain is called upon by the American President to join in an effort to neutralize an international terrorist threat. Escalating tensions within the Russian Federation lead experts to believe there is a conspiracy to destabilize its Western rivals. A mysterious arms smuggling gang known as the Citadel is suspected of bringing arms into the US for a series of terror attacks. Shanahan and Gawain are teamed with EUROPOL agent Lucretia Corcosa in an effort to infiltrate the ring and assassinate its leaders.