When a soldier returns from an overseas deployment and finds that the family home has completely vanished, he sets out to find his home and to discover who he really is.

There’s some interesting cuts to shorten this without changing the meaning.
—–
“When a soldier returns from an overseas deployment…”
“When a soldier returns from deployment”
(Deployment implies overseas, so overseas isn’t needed)
—–
“And finds that the family home has completely vanished…”
“And finds his family home has vanished…”
(One thing I find in my first drafts; overuse of the word ‘that’. Many times it can be cut)
{I used alt-f to find “That” and go through my entire screenplay, I also use alt-f for the word “is” as well}
(Also, you don’t need to say ‘completely vanished’, since ‘vanished’ means the same thing)
—–
“He sets out to find his home and to discover who he really is.”
“He sets out to find his home and possibly himself.”
(This one is more a matter of taste, not really an edit, I might even use the word Journey even though it has a few more letters)
“He journeys to find his home and possibly himself”
—–
Anyway; hopefully you can see how I made those cuts and why. Loglines are great practice for script editing. If you can cut a logline to 25 words, you can cut unnecessary words in a script as well.

Hope that helped, good luck with this!