UFO - an unidentified flying object.
Keep your eyes peeled/skinned - to watch very carefully for something
Bound to do something - certain to do something; destined to do something
Sooner or later - at some time in the future
Slavery - the state of one bound in servitude as the property of a slaveholder or household.
Cruiser - a large fast warship; smaller than a battleship and larger than a destroyer