"Tell me what we've got" Detective Greenly instructed as he walked purposefully up the short path to Harriet's front door, where a nervous Jane was stood waiting.

"Harriet Morgan, sir. She's not come home. I know it's been less than 24 hours, but since she ID'd the body in your murder case, I thought it would be a good idea to let you know…" Jane hesitated, looking at Maura's nervously fidgeting hands, "just in case."

"And what do I call you?" Detective Greenly reached out a hand as he looked Jane up and down.

"Detective Jane Rizzoli. FBI. Formerly Boston Homicide."

"John Greenly. Oxfordshire Police."

After a round of pleasantries, Jane followed the detective into Harriet's empty house.

Sitting on the couch with a mug of hot tea, a still shaking Maura explained Harriet's dinner plans for the evening.

"And this… professor. Which college does he work at?"

"Victoria, sir."

"And do you happen to know if he lives there?" Maura shook her head.

"I have no idea."

"Paul!" Detective Greenly summoned over a silver-haired officer. "Call central for me, would you? Ask them for the home address of Elias Kaplowitz. Professor at Victoria College." The uniformed officer nodded, plucking his phone from his belt as he walked towards the kitchen.

"Ladies, I've spoken to Agent O'Neill on the way over. He's happy for you to assist in the search- in fact, he insisted. But no guns. And you stay safe." Detective Greenly looked sternly at Jane. Gulping, she wondered what the FBI had told him about her.

Nodding, she agreed. "Understood."

"246 Sycamore Avenue" Paul's voice carried into the living room.

Picking his keys up from the coffee table, detective Greenly drained his tea.

"Let's go."

/

The tall regency terraced house was dark when the two patrol cars parked outside.

When there was no answer at the door, officers used a battering ram to break through it. Following the thudding footsteps of the police, Jane and Maura walked cautiously into the house, bodies brushing accidentally against one another as they navigated the narrow hallway.

"Negative" came a voice from the front of the line.

"Upstairs" Detective Greenly instructed. Turning to Jane and Maura, he spoke quietly. "Can you think of anywhere else they might have gone?"

Clearing her throat, Maura spoke. "Last time, we met at his office. If… if she had questions about the murders, about the codes, he might have taken her there."

"Sir!"

Following the sound of the officer's voice, the three of them quickly ascended to the first floor.

"In here."

Kaplowitz's home office looked as if it had been completely ransacked. Boxes and papers flooded the floor, cupboards had been opened and emptied.

"Get the forensics unit in here. We need to collect as much evidence as we can."

Scanning the room, Jane spotted a clean rectangular space on the floor. Carefully walking over, she pointed to it.

"There was something here. A… A box. Or… or a suitcase?"

Crouching next to her, Maura nodded. "An object, something dense and cuboidal, sat here for a long time. I hate to guess, but I would agree with Jane. There are four small indentations in the pattern- it could definitely have been a suitcase…"

Jane smiled as she heard Maura complete her sentence under her breath.

"… amongst a plethora of other similar objects."

Detective Greenly nodded. "If he took the suitcase, do you think he did this himself?"

Jane shrugged. "It wouldn't be the first time someone's tried to cover their tracks by making it look like a crime scene."

"So where would he have gone?"

Maura shook her head. "I'm not sure. The only other place I know of is his office at the college."

Detective Greenly turned on his heel and began to walk down the stairs. Lifting his radio to his mouth, he requested another unit meet him at Victoria College.

"Your expert opinions are very welcome to join me?" He offered, gesturing to his car as he unlocked it.

Jane and Maura quickly clambered in, buckling their seatbelts as the detective turned on the engine and the siren.

"Jane?" Maura's eyes were wide, full of fear and unanswered questions, as she looked across at her friend. Reaching out, Jane took her hand in her own and held it tightly.

"I'm here. I'm here."

/

An older sergeant greeted the three of them as the car pulled up outside Victoria College.

"There's nothing in the visitor log, and the CCTV doesn't work."

Jane shook her head. "It never does."

"We waited for you before we entered. It's your call, boss."

Detective Greenly walked confidently up to the door of the college, and into the building.

"Office is at the end of the corridor. I want every inch of this place searched. Smith, Peters, you take the left wing. Harrison and Lee, take the right. Listen out for one another, use your radios if you find anything. Two officers on the door at all times. Nobody enters and nobody leaves. Ladies, with me."

Jane and Maura followed Detective Greenly and two more police officers through the corridor and towards Kaplowitz's office. Nodding to the officers, Detective Greenly stood back as they broke through the locked door.

"Sir".

Maura, noticing the urgency in the officer's voice, pushed past the Detective and into the room. "Please" she said, more with her eyes than her voice, "this is what I do."

Harriet was laid in the middle off the office floor. A pool of vomit sat beside her pale, swollen cheek.

Walking cautiously over, Maura pressed two fingers against her friend's neck and checked for a pulse.

Looking up, her eyes met Jane's. "Call an ambulance. She's still alive."

Turning her onto her side, Maura examined Harriet's flaccid limbs and mentally catalogued what she found.

No external evidence of a struggle. No bruising, aside from her temple and around her mouth.

"Detectives" Maura addressed both Greenly and Jane, not caring that Jane's title wasn't quite correct any more. "I can't be certain until I see a tox report, but Harriet appears to have been poisoned. There's evidence from her mouth that she has had at least one violent seizure."

"Rachel Maloney was poisoned."

"Exactly."

Detective Greenly nodded. "So we need to find this Kaplowitz guy. Now."

Walking away from the room, Jane and Maura could hear him ordering a wider search for the professor.

"He won't get far" Jane reassured Maura, who was crouching over her friend, doing all that she could to help her.

"She's stable" Maura was clearly more comfortable focussing on her role. "She… she vomited, which is a good thing. It means she's got some of the toxin out of her system."

"But why leave her?" Jane questioned.

"If she passed out after her seizure, he might have thought she was dead."

Pulling on a pair of gloves, Jane began to walk around the room opening drawers and cupboards whilst they waited for the ambulance to arrive. There were hundreds of books, and more of the same papers they had found in his house. In the corner of the room, an antique bureau sat. Locked.

"Can you still pick locks?" Jane looked across at Maura.

Nodding, she scanned the floor, picking up a rogue paperclip and unravelling it.

The bureau lock clicked, and Jane carefully lifted the polished wooden lid.

Inside, sat on the desk, was a long metallic machine, with two rows of embossed keys and a rotor system.

"That's it." Maura pointed. "That's Mercurius."