The headache came back, and with it, William was reduced to his knees.

“What the hell was that? Are you sure we are okay?” asked Adrian.

“Absolutely” answered Ludmila.

“Anyways I’d rather get out of here before it reaches zero” interrupted Ross.

“To open the door we need to solve a puzzle right? Then our main clue would be these” he continued while pointing at the door.

“H-B-K-Q-P-P-P-P and the drawing of two cards? What does it mean?” asked Adrian.

“It must be some type of code” said Rose while toughly inspecting the door.

“To solve it me must first focus on how to, before analyzing the clues” stated Victoria.

“What do you mean?”

Victoria pointed at the black and white buttons.

“They probably need to be pressed in certain order, and if it wrong it will make that noise” she stated.

“Then the code must be a sequence of white and black, and that code must be given by the sequence of letter printed on the door” deducted Ross.

“If it is about two cards then, it would make sense that the white button refers to the red cards, and the black button to the black cards” Adrian quickly noted.

“And the letters are a form of referring to the every single card” Victoria was on track.

William was surprised how well everyone adapted to the situation, he was excluded completely.

“But… what´s the link between the letters and the cards then?” asked Ludmila.

Everyone was deep in thought.

“How much time left?” William couldn´t see the numbers.

“Eleven minutes, but there´s nothing to worry about” Ludmila smiled at him.

“Even if it is about checkers or chess, what´s the link between them and the cards?” asked Adrian.

“Chess” said Victoria.

Ludmila lightened up, she seemed to follow her train of though.

“H-B-K-Q-P-P-P-P are initials for chess pieces, and even gives out the order!” followed Ludmila.

“What? How?”

It took William a few seconds to figure it out.

“H for horse, B for bishop, K for Knight, Q for queen and for Pawn, it all makes sense”

“But, without knowing if they are white or black it´s meaningless” added Ross.

“No it´s not, even we don´t know that we can try every possible combination before the time runs out, there can´t be so many!” you could see Adrian was happy.

“Two hundred fifty six possible combinations” cut Victoria.

“If the initials are for every piece of chess then we need it´s coordinates” she added

For a few seconds everyone remained silent.

“I´m at my limit, thinking any further won´t do any good, I´ll try the combinations” said Ross while putting hand on the buttons.

Quickly enough he inserted the first sequence and the wrong sound didn´t delay.

BEEEEEEEEEEEEEEEEEEEEEEEEP

As if he didn´t heard it Ross kept pushing the buttons one after the other, trying every possible combination of the eight buttons.

BEEEEEEEEEEEEEEEEEEEEEEEEP

BEEEEEEEEEEEEEEEEEEEEEEEEP

BEEEEEEEEEEEEEEEEEEEEEEEEP

BEEEEEEEEEEEEEEEEEEEEEEEEP

Over and over and over, William collapsed, and he wasn´t the only one. The noise was insufferable.

BEEEEEEEEEEEEEEEEEEEEEEEEP

BEEEEEEEEEEEEEEEEEEEEEEEEP

William, maybe thanks to the adrenalin of the moment finally could see the numbers on the countdown.

“Only three minutes left”