I agree that the base is now compromised, but it seems foolish to just up and abandon it. After all, locating and then destroying a supervillain base- particularly when innocent hostage police officers are in danger- is the sort of thing that draws heroes like rotting meat draws flies, and since the base is written off one way or another anyway, we might as well use that as the centerpiece of a minor scheme to get more Mania. Mania in all things. So let's have some fun.
How about this?
[x] Order the investigators captured. Incapacitate them so they don't see anything.
- [x] Use hacking into their phones/radios and voice synthesizers if necessary to have them report that everything is fine and allay suspicion briefly. This will buy time.
- [x] Bring in digbot and bruiserbots to quickly form extensions to the base, which we fill with convincing mock-ups of stuff to make it look like a major location of ours- significantly larger than even our medium base actually is. Include destructible escape tunnel to elsewhere. Include prison for PIs.
- [x] Rant to captured PIs about how their tenacity in discovering our clever double ploy to hit the city with a wave of deadly mole monsters and establish a secret base from which to carry out all kinds of sinister plans has served only to ensure their own doom. Repeat as amusing.
- [x] Seal base entrances, but remotely monitor the whole area. Heroes will inevitably find and penetrate our seals after reviewing available evidence.
- [x] Fight heroes with bruiserbots. Rant remotely while fighting is ongoing, and gather some data on hero-fighting.
- [x] Rant to the heroes after our bots lose that they'll never catch us... particularly if they waste their time saving our hostages from the explosion our base is about to go through! Mwahaha!
- [x] We were never actually there, but have vehicle flee down the escape tunnel anyway just to make it look good. Then collapse the escape tunnel, blow up the base after the heroes escape in the nick of time, and kick back with a job well done.
- [x] Press release to the city the next day about how while the heroes may have destroyed our base and ruined far too much of our glorious work, they haven't seen the last of us, and we only grow stronger! They will rue the day they challenged the might of Revan!
Perhaps the plan's a bit too detailed? Well, whatever; I was having fun writing it.