Callum’s precious Auntie Liberty ruined my life. She took full credit for the work that was EQUALLY shared between us, lied to everyone about the extent of my involvement and took that lie to her grave. I was furious.

But that’s not a reason to kill her nephew.

I’ll tell you what is though. If Callum was somehow unable to be the one to disburse the donation, or if something were to happen to him, then the responsibility fell to me. Callum made it quite clear to me on several occasions that he had no intention of passing on his responsibility, in fact quite the opposite. He was loving the attention and the power. And it was killing me. So I killed him.

I snapped. My entire career I’ve been overlooked, taken advantage of, underestimated… Enough was enough. I had to take matters into my own hands. And the only way to do that was to get rid of Callum. So I poisoned his tea. And then, just to make sure, I followed him out the fire escape and pushed him.

I killed Callum Bell.

Callum Bell crossed me. Boy did he cross me. Abandoning his post in my lab to follow his bit of stuff into Physics, I mean how ridiculous is that?! I’d have probably forgiven him for that (I expect he’d have come crawling back eventually), but there was the matter of the substantial funding he was the caretaker of. I am acutely aware that everyone wanted their hands on that money for lots of very worthy and exciting projects. But I needed that money.

I had recently committed myself to secret monthly payments to Sarah Bellamy. Callum got the poor girl pregnant and she was desperate. Us scientists don’t get paid the big bucks and she was only asking for enough to support herself and Callum’s child. But Callum callously refused. And I couldn’t see her suffer, so I decided to pay her - in cash - and say it was from Callum, thinking I’d be fine financially because the donation was definitely coming my way, so my salary was bound to increase.

How foolish was I?

Not foolish enough to kill him, if that’s what you’re wondering. You’ll have noticed, I’m sure, that the person signing out the arsenic in small quantities over the past week or so tried to cover it up by signing my initials, but their penmanship leaves a lot to be desired - nothing like my handwriting! Also, I am a stickler for the rules and at no point is anyone permitted to bring food or drink into my lab. If Callum’s tea was poisoned and the only time I saw him was in my lab, how could I have had access to his cup?

I’m not going to lie to you, Callum and I were not friends. I’d go as far as to say we hated each other.

Which is why I was shocked and truly mortified after our one night stand. What can I say? Hate is a pretty strong emotion, it must have gotten the better of us. Or the drink did.

Anyway, having promised not to lie to you, I do have to come clean about something now. I’m not pregnant. Never was. But I saw an opportunity here. Callum had just found his way into more money than anyone would know what to do with and what I asked of him to support his ‘baby’ was seriously a drop in the ocean. He wouldn’t even have noticed! And I’d have figured out a way to make it work for as long as I needed it to. I might have been able to convince him to fund my project because of it. Now we’ll never know.

He never found out I wasn’t actually pregnant. Not for sure anyway. And I expect he’d have kept paying to keep me quiet. So I had no reason to want him dead. In fact, whoever did it has really screwed things up for me!

You can call me all the names you want. Gold digger, leech, exploiter… I’ll hold my hands up to it. But I am not a murderer.

Callum Bell was a catch. He’s smart, good looking and the richest man I had ever met. Or he was about to be. And he was always generous with his money, even when he didn’t have all that much, so I knew I had it made with him.

Did I love him? No I didn’t. I doubt I ever would have. But I would have loved my life with him… and his money.

So why would I have killed him? Oh the Will thing. Yeah I was researching that, of course I was. I wanted to make sure I was covered. I knew something like this could happen - I wasn’t wrong was I?! But I hadn’t even spoken to Callum about it yet, so I’d have been really stupid to get rid of him before I knew what would happen to his money.

Besides, lowly lab techs have no access to any chemicals, let alone arsenic. Peter has them all under lock and key and I would have had no way of getting my hands on it.