Captain John Christopher
Military Police Sergeant
Transporter Chief Kyle
en route to Starbase 9 for re-supply the Enterprise encounters the peculiarly
strong gravity well of a black star. By applying maximum power from the
warp engines the ship is able to break free but is thrown away from the
phenomenon at an incredible speed, in a 'slingshot' effect, as the gravitational
pull is broken. The ships systems go down under the strain, and, after
effecting repairs to restore auxiliary power, they find themselves in
a low orbit around Earth.
Kirk orders Uhura to contact Starfleet to advise them of the situation.
They manage to climb high enough to attain a safe orbit but Starfleet
cannot be reached. Instead, Uhura is picking up old-fashioned radio broadcasts
about the first lunar landings. The Enterprise, it seems, has been thrown
back in time to the late sixties.
While in low orbit the Enterprise was detected by U.S. Air Force radar
and an aircraft, piloted by Captain John Christopher, has been sent to
investigate. The plane closes to visual range and Kirk orders the use
of the tractor beam to hold it at a distance but, unable to take the stress,
the 'primitive' aircraft starts to break up. Kirk is left with no choice
but to save the pilot by beaming him aboard. Kirk meets Christopher in
the transporter room and explains the situation to him. By now power has
been restored to the deflector shields rendering the Enterprise invisible
to ground radar but the damage has already been done and their time line
is already in danger due to Christopher's 'view of the future'.
Following a meeting, at which Spock announces that Christopher made no
significant contributions to history, they plan to keep him aboard but
Christopher has other ideas. He has a wife and children back on Earth
and also feels a strong duty to report what he has seen. With this in
mind, he manages to escape and gets as far as the transporter room where
Spock and Kirk manage to stop him. Spock has been making further enquiries
in the history databanks and has discovered that, although Christopher
himself made no impact on history, he has an, as yet, unborn son to be
called Sean Jeffrey Christopher who is to lead the first successful Saturn
expedition, and so must now be returned.
Kirk and Spock beam down to the Air Force base in order to remove any
recorded references to their appearance. Various events occur, including
the momentary beaming up of a military policeman by mistake, but their
mission is a success. Their only problem now is to somehow return Captain
Christopher to Earth. Scotty and Spock make a detailed examination of
the events leading to their current situation and come up with some calculations
that will allow them to perform the manoeuvre in reverse by using the
gravitational pull of the sun.
They theorise that, if transported at exactly the right moment on the
return 'trip', Christopher can be returned to a moment in time shortly
before he got his first glimpse of the Enterprise. Christopher returns
to the transport room while Spock makes the necessary arrangements. At
first the Enterprise travels further back in time, but as the 'slingshot'
effect takes over she is thrown forward into the future at a fantastic
The incredibly accurate transportation of Christopher is successful. The
Enterprise goes through incredible stresses, braking heavily at just the
right moment to end up in her own time again. The engines start to give
way and the whole ship shakes violently but she holds together and, as
they slow to 'normal' speeds, Uhura receives an incoming message from
Starfleet meaning that they are back 'home'.