Just thought I'd share this with the boards, as of all the AOs I feel Shub-Niggurath's flip-side builds to something that then never manifests. I came up with this as a way of giving the game a more definitive conclusion, and it worked really well for me. In fact, it gave me one of my very best games. I'd love to hear how it plays out for someone else, should they try it.

So, when Shub-Niggurath awakens, play as normal until (if and when) she achieves her standard victory conditions.

At this point, instead of losing the game, introduce a new phase to the round - The Hunt phase. And for a little flavour:

The unholy horror of Shub-Niggurath has woken and gathered her evil around her. Now, the mother of monsters calls out to all the terrors of the world. Everywhere is unleashed a tide of death and madness, seeking to destroy all those who would defy the dark mistress. Now, the Hunt begins....

The Hunt phase takes place after the Encounter phase and before the Mythos phase.

During the Hunt phase, all monsters on the map begin actively hunting the investigators (with exception to Shub-Niggurath and any location-specific monsters, such as Serpent Men, Giant Penguins, etc).

Monsters move one space closer to the nearest investigator, or, if there are three or more monsters grouped together, they each move one space along different paths to create a slowly spreading monster-net.

If a monster moves into a space containing an investigator, it immediately attacks that investigator (or investigators) and remains on the space if not defeated.

If a monster moves into a space adjacent to an investigator, it may ambush that investigator (but only one, if there are others sharing the space). If the monster is not defeated, it then retreats back to its original adjacent position.

At the end of every Hunt phase, each investigator that does not have a Hunted condition gains a Hunted condition.

When Doom would advance, spawn 2 monsters in the Heart of Africa.

The game continues until Shub-Niggurath is slain or all investigators are defeated.

(...)play as normal until (if and when) she achieves her standard victory conditions.

At this point, instead of losing the game (...)

So this variant makes Shub strictly easier than she is now?

(...)play as normal until (if and when) she achieves her standard victory conditions.

At this point, instead of losing the game (...)

So this variant makes Shub strictly easier than she is now?

There's no escaping the fact that it does, but of course to say it's easier is not the same as saying it's easy. Far from it. For all intents and purposes I'd consider the game still officially lost, but it certainly makes for a more exciting conclusion.

In fact, while I'm here I'd like to record for posterity an outcome of this scenario, which was truly awesome.

So, the hunt was in its first round and Lily Chen moved to South Africa, ready to take on Shub the following round (she was armed to the teeth and this was before the rule of having to fight non-epic monsters before the epic, so I figured she'd try and take Shub down as quickly as possible). Trouble was she'd have to survive a veritable army of seven monster attacks before she could attack next round.

Up steps Lola, in full action hero mode, to nobly stand beside Lily and take some of the heat. Meanwhile, Jaqueline (who had plumb the void) teleported to the Himalayas to escape impending attacks, while Leo was about to get murked in Beunos Aires (as he tends to for me).

I rolled a die to decide whether each monster attacked Lily or Lola and five of the seven monsters went for Lola. The actress put up a tremendous fight, defeating four of the beasts before finally succumbing. Lily then mopped up the rest, but not without taking some unexpectedly crippling damage. Her attack on Shub seemed destined to fail.

The following round, Jaqueline used plumb the void to jump Lily to the Himalayas, which was the only space on the board that was currently free from immediate danger. However, a group of six monsters were converging and would attack the following round.

Of course, only one of them could then be teleported out of harms way and seeing as Lily's chances of successfully casting the spell were slim, she traded all her equipment over to Jaqueline. I could practically hear the dialogue between the two characters.

Next round, a now super-powered Jaqueline teleports straight to the Heart of Africa, while a wounded and entirely unarmed Lily makes a futile last stand against the incoming horde. She fought well, but inevitably fell.

To cap the drama, Jaqueline goes on to beat Shub.

Sure, officially I'd lost that game, but I'll never forget what happened afterwards