Jestersama
First Post
Right. The key is to narrate it so that PCs who fail a check fall behind or are moving slower or otherwise express to them that they're still in the chase (at least until 3 failures) but they just lost some ground.
My advice is to manipulate their expectations. Heck, drop names from a completely different Lovecraftian story that are either just red herrings or you've reskinned as what you need. Concealing the specifics works quite well this well - players fall for it until they start to catch on to the trick - but I don't recommend trying to conceal the genre this way. They know you're a Cthulu fan, roll with it, don't hide that, but obfuscate what really is going on, giving them metagame clues that make them think "Oh NO! It's Cthulu!"
Awarding magic items in 4e is a bit of a a PITA for the DM. I recommend you adopt the "inherent bonuses" rule from DMG2 (if you use the DDi character program, there's a box players can check to give themselves those bonuses equivalent to a magic item of their corresponding level). It's a numbers fix. This lets you introduce whatever magic items you feel are wondrous and appropriate to the adventuring setting, in this case, perhaps something like villain planted bombs that if the PCs can disarm they can reuse elsewhere? Maybe a few healing potions or scrolls stashed in the Baggage Car? A magic shovel or lamp or horn in the gnomish-run Engine Room?
Your use of minions in your encounters is smart then. Just beware if the party lacks a controllers, minion fights can become harder than they appear (likewise with a strong controller and all minions on the field at once they can become trivially easy). I recommend having 1 or 2 minions enter on the second round from an unexpected direction.
I think to answer these I need to know more about the Hood NPC. Who is he? Class and level? When mention making him incorporeal or a magic hologram, I immediately think you're trying to turn him into a recurring villain, is that right? In other words, you have them chasing someone you ultimately plan to let escape anyhow?
All I meant by non-combatant is that he wouldn't pose any real threat to them, just use whatever stats for a level 1 monster that you might need (probably defenses), and have him surrender instead of fight.
I was going to make him a psionic villain. Perhaps they could encounter him multiple times in the "heroic" adventure with a final encounter before they hit level 11.
I do like the idea of a high level minion, so when they actually hit him he just pops and escapes for the time being