"It was all obvious from the start. And yet invisible," Elizabeth Rizzoli stated. "It's not a tragedy to choose between right and wrong. In a tragedy, you only choose between right and right."

Nikki O'Laighin kept a close eye on her mother's service weapon, which she had placed on her lap within easy reach. The younger woman couldn't see whether the safety was off. The safety catch was on the lower side. "And no matter which right you choose - it's always wrong," the detective replied.

Elizabeth sat thoughtfully in her armchair, which she had inherited from her grandmother Angela, and was dressed completely differently from what Nikki was used to. Nikki had only seen her mother in elegant trouser suits and tailored blouses. Now that she was sitting calmly in front of her daughter with a look hinting at the inevitable, there was no sign of it. The worn-out T-shirt and jogging bottoms hardly looked good on Elizabeth. "I've had to make many decisions in the past few days," Elizabeth continued calmly. "And that's what I've done. What else could have happened? The tragedy was inevitable anyway."

Elizabeth had opened a bottle of her favorite red wine. The captain didn't look at her daughter. Her eyes were fixed on the front window, through which she could see the old villas directly opposite Elizabeth and Maggie's house. "You know those dog owners who get a kick out of pretending to throw a stick and then rejoice when the dog runs to get it?" she began. "The animals search excitedly and full of anticipation for the crappy toy, only to realize that there's no stick for them to fetch at all." Nikki refrained from answering. "That's just life," Elizabeth continued. "It just pretends to throw a stick for us. And then it laughs when we scurry off to look for it for the thousandth time. We'll never find it --"

The night seemed to lie ominously and like a dark veil over Boston. Although Nikki had only been told to go to her mother's house a few minutes earlier, for some reason, she seemed to be expecting her. "Have you been lying to us all this time, Ma?" the young detective asked in a tone with which she tried to suppress her fear of the answer.

Elizabeth smirked and took another sip from her red wine glass. "Sometimes you have to lie to many to protect individuals," she finally replied. Then she pointed to the bottle on the coffee table. " Would you like a glass, Veronica?" she asked but immediately corrected herself, "Oh no, you're still on duty."

Nikki shook her head, her eyebrows furrowed. "I'd love to understand you, Ma. What is it with this boy?" Now, for the first time in a long time, the detective noticed an emotional reaction in her mother. Even if she couldn't interpret exactly how this was to be interpreted.

Elizabeth took a deep breath and licked her lips. Then she leaned back, crossed her legs, and said, seemingly incoherently, "Forget the boy. We had an aquarium in our elementary school class back in the day." Nikki's breathing was shallower than usual. She tried to hide her tension, even though she knew she could not get away with it with her mother. "Every day, one of us children was allowed to feed the fish," Elizabeth recalled. "It went by the alphabet." Both Nikki and her mother were aware that time was of the essence. The other officers were waiting outside the house, and it couldn't be long before they lost patience. Nevertheless, Elizabeth continued dispassionately. "I stood in front of the aquarium daily and promised the fish that they would soon get food from me. There were always other children before me, but I didn't mind. Because I knew the day would come when it would be my turn. But then something happened. Your grandparents decided to send me to a different school. With a special support branch for the gifted. It had been in the pipeline for a while, but they preferred not to tell me about it. I would have protested non-stop; what six-year-old wants to leave her friends? And so it happened that I had my last day at school quite suddenly and unprepared."

"But you hadn't had your turn with the fish yet," Nikki understood.

"I thought my teacher would make an exception and put me first because I had to go. But she didn't. It probably didn't even occur to her because feeding fish was just too insignificant for her, and she wouldn't have dreamed that it could mean so much to a child. And so I had to leave my friends and my familiar surroundings without at least having fed the fish first."

Nikki looked at her smartwatch. "We have to go, Ma," she said then, her voice sounding brittle.

Elizabeth sniffed her red wine, put the glass on the coffee table, and reached for her service weapon. Nikki's heart rate increased for a moment. But then Elizabeth removed the magazine from the gun, put the safety on, and handed it to her daughter. "I never fed the fish!" she said and stood up. Then she smiled at her daughter and said, "I'm glad Nick sent you."

"It was the least we could do," Nikki replied in a strained voice and pulled out her handcuffs, albeit reluctantly." Ma, I'm sorry, but --"

"...you don't have to apologize, Veronica. Why should you?" Unprompted, Elizabeth turned around and put her hands behind her back.

And while Nikki now reluctantly handcuffed her mother, she explained as matter-of-factly as she could that it sounded almost sinister, "Elizabeth Rizzoli, you're under arrest. You have the right to remain silent --"