I, like most other people, have been stuck trying to explain what happend during Overture - and not given a single thought about how the sequel would begin.
I am really pleased with this one: after entering the "Shelter" you are knocked out and locked inside a small cell wich you have to escape. I can fully see the logic in that: a stranger breaks in, they lock him in.
The puzzles seem like quite long-shots, some of them, but very amusing. Flattening that coin looked great, and the part where the player have to deactivate power in order to proceed is a classic: it forces the player to endanger his own health.
That syringe puzzle was really great, I hope there are more of those. It really wasn't the nice puzzle you'd expect, you have to drain blood from a dead scientist.

By the way, this demonstration does bring alot of answers to the questions of Overture.
For one, Red saying "parts of my head are not my own" and now Philip have got someone inside his mind too.
Also it turns out Philips father did work in the shelter and was last seen in the library.. last seen by whom?

However, looking back Black Plauge really goes far away from my expectations. I thought I'd see the return of the hunter or some of his fleshy cousins, instead this is turning into an infection.
I love infections and viruses in videogames, though.
The only things I can complain at is the physics (Stacking a toolbox upside-down on a jug isn't realistic and when it all fell apart it looked stupid) and the animation of the zombie (Suddenly calling them Experiments doesn't feel right.. they feel more like scientists to me).

• In the end of Penumbra: Overture Philip was knocked out and thrown into a makeshift prison cell.
• The cell is where the game begins, except for a possible introduction film.
• In the cell next to Philip someone is being tortured.
• You find a coin wich you flatten, then use to enter a vent. The next-gen ventilation-tool from the tech-demo?
• In the starting cell you also find a glowstick and a note saying:
"Between light and shadow, exists an *entire* world. That world is *hecessanlly* our own. Get out, Now. O."
The words with stars around are to me, unreadable.
• The guy locked in Philip's cell before him escaped and you will find notes left behind by him. The most notes are written in blood, wich sounds very similar to Assassin's Creed.
• Later the coin can be used to obtain a soda, used to turn of a ice-cold gas leak.
• There is a new waving-air effect.. but does cold really make air wave?
• The flashlight and flares will reappear quite early in the game.
• One puzzle requires the player to turn off the lights, forcing him to put himself in danger. Smart move.
• One puzzle requires the player to clean a syringe using alchohol then drain blood from a dead scientist. Now that's the kind of puzzle I want more of.
• The wallmines are only activated by a living mass, or possibly only Philip, going through it.
• There is an infection going on. Obviously. My bets are it's called the "Black Plauge".
• One puzzle requires the player to trigger the emergency alarm to get past a locked door. Sounds risky.
• There will be a tutorial - what the heck?
• A character named "Clarence" is stuck inside Philip's head similar to how someone controlled Red. Perhaps it is caused by the infection, meaning that Philip is infected or perhaps the Elevated Caste leader is telephatic.
• Philip's father Howards last known location is the library. Last known location, by who?
• Doors disappearing is queer, according to Clarence. I agree.
• Clarence seemingly can manipulate all Philip's senses (At least hearing, sight and feeling), making doors disappear for an example.

...I think that this Clarence was standing in the end of the corridor... At least, it seems so to me at this point...