The last thing I remember as Marcus Chen is the screech of tires and the sickening crunch of metal. Then nothing. Then everything. I wake up drowning. Not in water—in memories that aren't mine. A lifetime of experiences floods through my consciousness like a dam breaking. I'm seven years old, watching my father executed for treason. I'm twenty, leading my first military campaign in Hispania. I'm forty, governing provinces with an iron fist. I'm seventy-three, standing in the Forum as the Senate declares me Emperor of Rome. Except I'm not seventy-three. I'm thirty-four. I'm Marcus Chen, associate professor of Roman history at Columbia University, and I was driving home from a conference when— "Caesar?" A voice cuts through my mental chaos. "Caesar, the Senate awaits your pleasure." I open eyes that feel ancient and heavy. The room swims into focus—marble columns, frescoed walls depicting gods and heroes, golden light streaming through high windows. A man in a white toga stands before me, his face creased with concern. Behind him, two Praetorian Guards stand at attention, their armor gleaming. This isn't a dream. Dreams don't have this much detail. Dreams don't come with two complete sets of memories warring for dominance in your skull. I'm in Rome. Ancient Rome. And somehow, impossibly, I'm Servius Sulpicius Galba—the emperor I spent three years studying for my dissertation. The emperor who, in my timeline, ruled for exactly seven months before being hacked to pieces by his own guards in the Forum. Today is January 15th, 68 CE. If history runs its course, I have exactly six months to live. "Caesar?" The man—Icelus, my freedman and advisor, I know without knowing how I know—steps closer. "Are you unwell? Shall I summon the physicians?" I need to say something. My mouth feels like it's full of sand, but I force words out. "No. I'm... I'm fine. Just a momentary spell." The Latin flows naturally, pulled from Galba's memories. "The Senate, you said?" "They await your response to their petition regarding the grain supply. The shortage has caused unrest in the Subura. There were riots last night." Right. The grain crisis. One of the many disasters that historically plague Galba's brief reign. In my old life, I wrote an entire chapter about how his fiscal conservatism and refusal to pay the traditional donative to the troops created the perfect conditions for his overthrow. I wrote about it. Past tense. As history. Now I'm living it. I push myself up from the couch—lectus, my brain supplies automatically—and immediately regret it. This body is old. Really old. My joints protest, my back aches, and there's a persistent pain in my left hip that Galba's memories tell me has been there for years. I'm used to a body that runs five miles three times a week. This one probably hasn't run anywhere in decades. "Tell the Senate I'll address them within the hour," I say, buying myself time to think. "And Icelus—bring me the financial records. All of them. Treasury receipts, military payrolls, provincial tax assessments. Everything." Icelus blinks. "All of them, Caesar? That will take—" "Then start now." He bows and retreats, clearly puzzled. Galba, I'm learning from his memories, wasn't particularly interested in the minutiae of imperial finance. He left such matters to his advisors while he focused on restoring "traditional Roman virtue" and cutting expenses. That approach got him killed. But I'm not Galba. Not entirely. I'm Marcus Chen, and I have something the original Galba never had: I know exactly what's coming. I know that Otho is already plotting against me, courting the Praetorian Guard with promises of money I refused to pay. I know that Vitellius's legions in Germania are preparing to march on Rome. I know that by December, four different men will have claimed the purple, and the empire will be drowning in civil war. Unless I change it. The question is: can I? Should I? Every historian knows the dangers of the butterfly effect. Change one thing, and you might unravel everything. But what's the alternative? Let myself be murdered in six months? Let Rome descend into chaos? I walk to the window—my old legs moving slowly, carefully—and look out over the city. Rome spreads before me in all its ancient glory. The Forum bustles with activity. The Palatine Hill rises to my left, crowned with imperial palaces. In the distance, I can see the Colosseum's construction site. No, wait—it's not the Colosseum yet. It won't be built for another couple of years. Right now, it's still Nero's lake, part of his Golden House complex. Nero. Dead by suicide just six months ago. The last of the Julio-Claudian dynasty. The Senate begged me to take the throne, to restore stability after his excesses. They thought they were getting a stern, frugal administrator who would clean up Nero's mess. They have no idea they're getting a 21st-century economics professor with a PhD in Roman history. A smile tugs at my lips despite everything. If I'm stuck here—and the persistent reality of aching joints and Latin thoughts suggests I am—then maybe I can do something no other time traveler in fiction ever managed: actually fix things. I know why the Roman economy is collapsing. I know the structural problems with the Praetorian Guard. I know which generals can be trusted and which are already planning rebellion. I know the future, and knowledge is power. But I also know that Galba's biggest problem wasn't lack of knowledge. It was lack of support. He alienated the army by refusing the customary donative. He alienated the people with his austerity measures. He alienated the Senate by being too autocratic. He tried to rule through fear and tradition, and it got him nowhere. I need to be smarter. More strategic. The door opens again, and a different freedman enters—Titus Vinius, one of my closest advisors and, if I remember correctly, secretly working with Otho to undermine me. "Caesar," he says with an oily smile. "I heard you were indisposed. I came to ensure all is well." "Perfectly well, Vinius." I study him with new eyes. He doesn't know that I know he's a traitor. That's an advantage. "In fact, I've been thinking about the grain shortage. And the troops." His eyebrows rise slightly. "The troops, Caesar?" "The Praetorian Guard, specifically. I know there's been... discontent about the donative." "A traditional gift, nothing more," Vinius says smoothly. "Your predecessor Nero was profligate with such payments. Your fiscal responsibility is admirable—" "And likely to get me killed," I interrupt. His eyes widen. "Come now, Vinius. We both know the Guard expects payment. Tradition matters to soldiers. I've been thinking perhaps we should reconsider." I can see the calculations running behind his eyes. This isn't the Galba he knows. The Galba he knows was stubborn, inflexible, convinced that his way was the only right way. "That would be... prudent, Caesar," he says carefully. "Though the treasury—" "Leave the treasury to me. I have some ideas about revenue enhancement that don't involve squeezing the provinces dry." I pause. "Tell me, Vinius. How loyal would you say Otho is?" The question catches him completely off guard. His face goes carefully blank. "Marcus Salvius Otho? He's been a loyal friend to you, Caesar. Since your time in Hispania—" "That's not what I asked. I asked about his loyalty now. Here. In Rome." Silence stretches between us. I can see him weighing his options, trying to figure out what I know and how I know it. Finally, he says, "Otho is ambitious, Caesar. As are all men of his station. But he has given you no cause for suspicion." "Yet," I say softly. "No cause yet."