Now yes, I agree the safest place to be if you've got psycho stalkers on your hide is Superman's house (okay, okay... I know the mythos, but I couldn't resist.)  The salvage factor here is, of course, that Lana has an ulterior motive in addition to her need to be protected from sociopaths;  she's looking for dirt on Clark.

Of course and barely-post-pubescent prime time drama is going to immediately introduce a red herring in a situation like this, and yes, we have one.  There is this totally obnoxious photographer that is just way too in love with Lana's photogenic side.  It's pretty obvious from the beginning that he is not the guy no matter how hard he tries to sell it.  It's too ingrained in the Smallville stalker formula; there is always a red herring.

So while Clark dutifully works at protecting Lana she snoops around and tries to find dirt on him - no, really... don't thank me Lana - and eventually, with Jimmies assist, Clark confronts the real baddie.  Turns out to be one of Lex's own security guys! Stereotypical menacing psycho stuff ensues until the baddie is finally brought to justice, Smallville style.

Lex finally returns and is more than a little peeved to find out Lana sought shelter at the Kent house.  Needless to say, he is prompted to do something extremely snide - this time, he drops by and gives Clark and invitation to their wedding so he can see what he is missing out on.  Clark sees green.

Smallville has really been held up to a new standard since the excellent Green Arrow episodes and the incomparable 'Justice'.  As far as run of the mill Smallville fare goes, 'Trespass' was tolerable... particularly if you had never seen the other eight or nine episodes it is a prototype of.  But seriously, if the norm is going to be episodes like Crimson and Trespass, it might be a good idea for Clark to finally throw on the tights and fly away,  permanently.