..which we're led to understand begins only a couple of weeks after the end of TVH
...But then again, it might be more like months. They have to swap the bridge module, after all!

Why did the ST4 costumers fuck up? It doesn't sound like something they would do lightly and without consideration, costuming a main character in a sequel. Especially after getting two sequels more or less right already. Did they just read the first half of the costuming instructions for ST3, which of course begin with "Doohan wears item 24B, the Commander pin"?
Timo Saloniemi