Emy G's speaker answers the question in the title head-on: nowhere. When we die, she believes, memory and body vanish and that's the end. She's relaxed about other people's beliefs, whether heaven, hell, or reincarnation, and says she'd simply nod along. But she still wants to make her own case.
Her main argument is that sleep is a kind of small death. We don't fear sleep, even though we can't be sure what it holds, so why fear the real thing? The "bug crawling up your spine" captures the nagging dread of not knowing, which she calls fear. She says she has "murdered" that fear, even if it makes her sound like a sociopath.
The mood is calm and a little defiant. The tone is casual, almost shrugging, until the last line turns the question on the reader: "But are you?" It leaves us unsettled, and perhaps a little challenged.