.... In some ways, "The Final Mission" warrants a '10' rating because this episode is where Wesley says his Star Trek goodbyes (for a time, as he would come back from time to time in later seasons). In other ways, "The Final Mission" warrants a '5' for hardly being able to hover above the mediocre line.
Wesley Crusher had long been the most annoying, pointless and least interesting and compelling character of the entire "Star Trek: The Next Generation" series. His constant out-thinking everyone and saving the day was, although downplayed significantly after the first season, used one too-many-times throughout the show. Season 4 grants Wesley one more day-saving episode to the pleasure and chagrin of us all.
The episode revolves around Wesley's last Enterprise task accompanying Captain Picard on a settlement mission before heading off to Starfleet Academy. When their shuttle crashes on a barren planet, Wesley has to keep Picard alive while trying to survive amidst a dangerous phenomenon and a irrational companion. Of course, the Enterprise cannot be around to save them if this Wesley-centric storyline is to exist - so the writers conjured up some half-brained b-story revolving around what is basically the removal of a runaway garbage truck to keep the Enterprise away from our struggling survivors. Meanwhile, the impending death of Captain Picard could only be ruined by the weepy presence of a wining Wesley Crusher. Luckily, Patrick Stewart has enough screentime to make this episode worthwhile; otherwise, "The Final Mission" would have been one to avoid.