Stay Alert! One Dead Body

Once on the second floor, Amadeus Falco walked proceeded with caution as he made his way slowly along the corridor of the hotel, checking for unlocked doors. supervising if the door were opened or closed. He took off his encumbering mask to be free in his movements. Afterall, the floor was empty. The guests were hobnobbing and the staff were all busy serving on the ground floor. Falco listened heard what sounded like a door flapping from beat because of the sea breeze that blew sweeping gently in from the lagoon. The inspector with wield his now cautiously held Beretta M51,  and moved along the wall carefully glided towards the sound like that of a hunter cat. It was One double room with a garden...  and has A opened window was left opened. Falco peeked.  gave a look inside. There was a velvet armchair, a round table with a lamp, some Venetian wall paintings pictures on the walls and a double bed. Falco went slipped into the room and he almost lost his balance despite with the caution of his cat-like grace. After regaining his composure, he checked for the cause...His shoes slipped on the floor, the inspector maintained the balance but when he watched his soles, there were pieces of flesh attached. The blood came out from under the double bed. Falco lowered and saw a dead body , his skin looked as bluish-grey as the Hassan’s chauffeur he saw in the Foscari Palace. Falco stretched his arm and took the card that was attached to the dead body’s breast pocket.

The "banana-peels" looked liked pieces of bloodied flesh. Gruesome but his experience instinctively took charge and began to survey the room.  There was blood oozing out from under the bed.  Upon a closer look, he discovered a body.  The dead man's skin looked bluish grey, just like those of Hassan's chauffeur whom he saw in the Foscari Palace.  On the body's breast pocket, a name card sticking out... Falco took it.

Stay Alert!

On the hotel's second floor Amadeus Falco walked slowly along the corridor, checking if the doors were opened or closed.

He took off his mask to free his movements. The floor was empty, as all the guests and the staff were all on the ground floor.

Falco listened to a door banging in the breeze that blew from the lagoon. He pulled out his Beretta M51 and crept forward, hugging the wall, until he reached the source of the noise. It came from the Double Room Garden, which had an open window.

Falco peeked inside. There was a velvet armchair, a round table with a lamp, some Venetian pictures on the walls and a double bed. He went in. His shoes slipped on the floor and he almost lost his footing. Checking his shoes, he saw that they were covered with organic matter.  Blood had pooled out from under the double bed.

Falco crouched down, careful not to contaminate the scene further,  and saw the dead body of Hassan's chauffeur, the skin bluish-grey in the dim light.  Falco stretched his arm and took the card that was attached to the breast pocket of the dead man. 

Hi Elisabetta. I've made some corrections to your text to make the English sound more natural. For instance, we use the verb 'to supervise' when we talk about someone supervising the work of other people, or supervising a process to check that it goes smoothly. It's better, therefore to say that he 'checked' or 'tested' the doors to see if they were open or closed.

"Falco listened a door beat" isn't grammatically correct. You need to rephrase, saying something like: e.g. 'He heard a door bang' / 'he listened to a door slamming in the wind' /  'a door was banging ceaselessly..' / 'a door creaked ceaselessly in the wind' / 'a draft caught one of the doors and slammed it shut.'

"The inspector wield his Beretta M51 and moved along the wall carefully": This isn't wrong, apart from you need to say 'wielded' rather than 'wield'. However, the language is a little stilted. Repharasing it as follows makes it sound more natural: "He pulled out his Beretta M51 and crept forward, hugging the wall, until he reached the source of the noise." We say 'hugging the wall' when we want to imply that someone is trying to make themselves less conspicuous or less of a target to a potential assailant by walking close to the wall rather than in the middle of the passageway. 

"...the inspector maintained the balance..." It sounds better to just say 'he kept his balance' or 'he kept his footing'. 

"...but when he watched his soles, there were pieces of flesh attached..." Firstly, you wouldn't watch your soles, you'd check your soles. Secondly, I thought it sounded wrong to say 'pieces of flesh attached.' 'Pieces of flesh' brings to mind chunks of meat like pieces of raw steak, which isn't what you're trying to convey, I suspect! So, I would either be more specific and say "He checked his soles and saw that they were covered with what looked like blood, brain matter and chips of bone'" or I'd be less prcise and say 'they were covered with organic matter'. 

'Blood had pooled from under the bed' sound better than 'blood had come from under the bed'.

I hope my comments and corrections don't discourage you, Elisabetta. Your novel is excellent and very engrossing, and your standard of English is very good. I'm just trying to make it sound more as though it's written by a native speaker, which is important if you ever intend to send this to a publisher. 

Stay Alert!

On the second floor, Amadeus Falco walked slowly along the corridor of the hotel, checking if the doors were open or closed. He took off his mask to be free in his movements. The floor was empty. The guests and the staff were all on the ground floor. Falco listened as a door slammed (?) because of the sea breeze that blew in from the lagoon. The inspector wielded his Beretta M51 and moved along the wall carefully. It was a Double Room Garden and had an open window. Falco looked inside. There was a velvet armchair, a round table with a lamp, some Venetian pictures on the walls, and a double bed. He went in. His shoes slipped on the floor, but the inspector kept his balance. However, when he looked aat his soles, there were pieces of flesh attached. Blood came out from under the double bed. Falco lowered himself to look and saw a dead body, its skin as bluish-grey as the Hassan’s chauffeur he saw in the Foscari Palace. Falco stretched his arm and took the card that was attached to the dead body’s breast pocket.