Unseen[1] is a naval thriller published in 1999 by Patrick Robinson; it is the third book in the series featuring Admiral Arnold Morgan, and marks the return of Ben Adnam.

The book differs from the previous two in the series in that it focuses less on the plot and heroes and spends more time on the character development of villain Ben Adnam.

During their confrontation, Adnam informs Morgan that Iraq was behind the terrorist attacks and suggests that the destruction of some dams in the country is sufficient retribution.

In the Epilogue, Ben Adnam, having been given a permanent job and a US passport, decides to come clean and inform Morgan that it was actually under the flag of Iran that he had destroyed the airlines.

Ben Adnam is somewhat unusual among techno thriller villains in that he is neither captured nor are any of his attacks thwarted by the "good guys"; even his death is at his own hands.