[Written for a prompt by MysteryThrillerIN . Word count – 999 words]

Dr Kaganov sighed in frustration as the body was taken away by the coroner, who was closely followed by two police officers. The steady ticking of the grandfather clock near the librarian's desk matched the thoughts that swirled around in her mind.

It doesn't make sense.

Shira paced around the bookshelves restlessly as Officer Lane re-entered the library. 

For the past two weeks, she had been working as an assistant librarian at the place at the request of the police force, who had approached her after a serial killer had gone on a killing spree right in the city library.

Certain that her skill of observation, especially of human behaviour, would aid them in tracking down the criminal, Officer Lane had roped in Dr Kaganov to monitor the visitors that dropped by every day, from an unassuming place behind the librarian's desk. Any suspicious behaviour would provide a plausible clue to the killer's identity.

"Aleksandr was my prime suspect," Shira broke the silence, ceasing her restless steps for a moment. She shook her head in perplexity.

"Now that he's dead..."

Officer Lane withdrew a piece of paper from his coat pocket and smoothened it out. He handed it to the psychologist as he gestured for her to take a seat.

"This was found on his body."

Shira glanced through the note, a frown creasing her forehead as she laid eyes on the last line.  She looked back up at the officer, who met her gaze expectantly.

"Another Alexandre Dumas quote," Dr Kaganov stated.

The previous two victims' corpses had yielded scraps of paper similar to the one they had recovered from Aleksandr. Crumpled notes with short lines of text. The otherwise simple quotes from a couple of classic literary works had taken an ominous undertone in the past two weeks.

Shira's mind went back to the quotes on the previous two notes.

"Know you not that you are my sun by day and my star by night?"

"The voice of human nature is nothing but one prolonged cry."

The quotes, from Queen Margot, and The Man in the Iron Mask, had both been obtained from books by Alexandre Dumas. It was a taunt from the killer, undoubtedly, by their use of quotes from the  books that the victims had only recently borrowed from the library.

"And now, this," Dr Kaganov muttered, glancing down at the new note in her hand.

"The merit of all things lies in their difficulty."

"The Three Musketeers?" Officer Lane ventured, his own memory hazy about the story he had read in his childhood. Dr Kaganov nodded.

She promptly stood up and strode up to the librarian's desk, taking the officer by surprise, although he had learnt not to question her methods.

Dr Kaganov had assumed her new "job" as an assistant librarian to the woman who had filled the librarian's designation for the past three years.

Her morning therapy sessions with the occasional client amplified Shira's need for flexible work hours, but despite reporting a little late in the mornings to the librarian's desk, her recent observations had been coveted by the police force.

Although the librarian herself hadn't warmed upto the sudden companion over the past week.

"Alana, I need access to the library management system, to view the books borrowed in the last month," Dr Kaganov told the young lady politely, although the latter sensed it wasn't a request.

In a minute, Shira was scrolling through the digital records on the librarian's computer, before pausing at the desired date.

"Name: Malcolm Alexandr.
Item borrowed:  The Three Musketeers (Alexandre Dumas).
Date: 13.04.2023."

As Shira glanced through the third victim's history, it dawned on her that her suspicions about him had been inaccurate. She scrolled down the page, looking for a particular author's works. She inhaled sharply as the result popped up on the system.

"Name: Lea Abramov
Item borrowed: The Count of Monte Cristo (Alexandre Dumas).
Date: 15.04.2023."

"We've got our next victim, Officer."

*****

The city library had always been a quiet, secretive place, and at times, even ominous.

As the old lady crossed the bookshelves in the chilly archives, she wasn't surprised that a man had been murdered here. The very thought of murder made the woman shudder, and her sole objective was to return the book and exit the place as soon as she could.

"Alexandre Dumas... Here we are," she murmured, pushing the book back into the empty slot that seemed to have been awaiting the Count of Monte Cristo's homecoming.

She quickly stepped back from the shelf, and as though anticipating some ill fate to befall her, stood listening for any unusual sounds.

"Mrs Abramov, may I help you?"

The old lady spun around at the sudden remark. The young librarian stood near the spiral staircase, a polite smile plastered on her face.

"Thank you, Alana, but I was just on my way up," Mrs Abramov replied shakily, having just recovered from the sudden apparition of the librarian. She smiled at the young lady, who remained motionless at the stairs.

"I'm here to help you, Mrs Abramov," Alana stated, advancing towards the woman.

"Whether you need it or not."

The sound of a revolver cocking was all that preceded the gunshot that echoed through the archives. What the librarian hadn't taken into account was the flash of silver that streaked through the air as the old woman had ducked and advanced towards the attacker.

The two women wrestled to the ground, before the gun lay abandoned under a shelf and the young lady had sustained two knife wounds on her shoulder.

Dr Kaganov got to her feet and brushed the grime from her clothes, the dishevelled grey wig falling to the floor.

"So, the library got so boring that you needed a hobby?"

The librarian growled indistinctly as a pair of less than comfortable handcuffs bound her wrists.

"You stabbed me!" She wailed, gasping at the blade that Shira had pocketed.

"You tried to kill me. We're even."