Possible Clues:

• Fish in river is not pike
• Dire disaster -- trapped by high-explosive missile
• In river I had Poseidon's weapon
• Weapon resembling the letter psi
• Weapon I'd placed in river
• Missile shelter Rhode Island Democrat enters
• Move in explosive missile
• Weapon's journey north in case of target
• Weapon that's free, wrapped in canvas
• Missile system I'd found in river