Kitty Pryde is stuck. Stuck! Stuck! Stuck! But enough about her art. She's been permanently trapped in phased form. I don't know how she's supposed to eat or drink or breathe whatever, but I assume Marvel Physics takes care of that. She's so far gone that she can't be heard, which is a great idea - she's reduced to telepathic communication with Betsy. But what can they do? Especially when they have no idea how to get in contact with Beast.
Ask Reed Richards of the Fantastic Four, obv. Unfortunately, it turns out he's useless. Well, that's what it looks like from the X-Men's point of view. Really, he's having a big crisis of faith having discovered evidence that he had secretly known about the risk posed by cosmic rays prior to the FF's transformational first journey into space. He agrees to go with them to Muir Island to do some tests, but after doing them demurs. Wolverine threatens him blah blah steal the equipment blah blah Doctor Doom blah blah blah offers to help blah blah blah Storm blah blah blah Reed blah blah blah Yancy Street blah blah blah Latveria blah blah blah Reed changes his mind blah blah Doom and Reed's rivalry blah blah blah Kitty is healed.
Yeah, I'm that enthused about it. Part of the problem is that most of the interesting internal dynamics are FF stuff, and I've no context for that. Is the "Did Richards secretly plan this all along?" plot a new idea that Claremont has somehow managed to have after 25 years of FF comics, or is this a hackneyed old thing? There's some mileage to be had about the "Can the Fantastic Four trust the X-Men now that they are working with Magneto?", but the answer is "what the heck, why not", eventually turning into a handshake between Magnus and Reed.
The relationship between the X-Men and Doom is more interesting. To my knowledge they've only met once before, in that Murderworld arc. In this story, Doom spontaneously offers help after Reed rejects them. He says "my reasons [...] are my own", but you don't need to be a Fantastic Four fan to figure out that succeeding where Reed gives up has got to be part of it.