The weakest of the 'old' crew Star Trek films, this film suffers from an awful script and obvious budget constraints, particularly in the mishandled finale. The bones of a good movie are here, and the directing from Shatner is not as bad as is commonly made out, but the characters end up speaking and acting way out of the style that the previous 3 films had carefully established. Lawrence Luckinbull is convincing as the renegade Vulcan with msyterious and mystical powers to influence people and these powers are responsible for some of the best scenes, particularly for Deforest Kelley who shines as 'Bones' McCoy in this his second last movie. However, as good as those scenes are, they ultimately do not advance the plot, and end up feeling as more of a distraction. A great score from the ever reliable Goldsmith and some funny scenes in Yosemite between the main three are not enough to cover the gaping chasms in the plot, and the frankly embarassing attempts at humour serve only to alienate even die hard trekkies. All in all, a wealth of possibilities which although it fails to deliver, has its moments. Watch out for the pool table in the bar brawl scene...