It could also be something he's shared on his official website or social media platforms. Sometimes authors release exclusive content on their own channels. So, look for it on his Twitter or his official website. However, if it's a really 'secret' story, it might be something only shared with a select group, like at a convention or a special fan event.
Another possibility is that it's a story that's part of an upcoming book. In that case, you won't be able to find it just yet. But you can keep an eye on announcements about his future publications. You could also join fan communities dedicated to Brandon Sanderson. Fans often discuss and share information about any potential hidden or secret stories, and they might be able to point you in the right direction.
Chapter 263, "Offering Advice, An Elder Brother Like a Father", is the clearest early answer because it turns Cold Resistance Level's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Big sis, second sis, I brought soup." "Coming!" Outside the main... and follows through with From my observations in recent days, deliberate carders like you not....
Chapter 290, "Rich Harvests—Should We Store Land or Men?", is the clearest early answer because it turns Xia Hong's situation into a concrete plot event. The setup is The price of the great victory at Ning Yuan Hill was clearly much..., but the pressure keeps building through The Cloud Dragon Army rushing in from the north had only just over....
Chapter 207, "Reforming Corvée Labor, Changes in the First Year [Happy New Year!!!]", is the clearest early answer because it turns Great Xia's situation into a concrete plot event. The chapter gives readers a real answer by opening on On the southern side of the Great Xia Valley, there is a giant... and ending on Brother, how long have you been in Great Xia?.
Chapter 294, "Empty-Handed, Slow on the Uptake (Part 3)", is the clearest early answer because it turns Xia Hong's situation into a concrete plot event. Early on, The Cloud Dragon Army also has quite a presence, but compared to the.... By the end, Li Tiancheng, clothed in white and with hair like silver threads,....
Chapter 213, "News from Long Mountain, Ecstasy, and Riot", is the clearest early answer because it turns Cheng Ping's situation into a concrete plot event. It opens with The Beehive's base is underground and relies on lamp lighting at all... and closes on Didn't you want to see the knives?. The key payoff is that the chapter exposes hidden motives around Cheng Ping, so readers can finally see how the conspiracy layer of the plot is actually moving.
Chapter 251, "Understanding—Win Hearts First, Then Take the Next Step", is the clearest early answer because it turns Xia Chuan's situation into a concrete plot event. Early on, The distribution of Solidified Fire Oil proceeded in an orderly.... By the end, To Chen Yingyuan, these six, along with the thousand Longyou troops,....
Chapter 257, "Building a Straight Road, the Beast Meat Issue (Part 2)", is the clearest early answer because it turns Xia Hong's situation into a concrete plot event. Early on, Xia Hong heard this and his eyes instantly lit up.. By the end, The iron mines and coal mines under the names of Beehive, Wushuang,....
Chapter 225, "Council at Long Mountain, Li Xuanling's Decisive Action (Part 3)", is the clearest early answer because it turns Li Xuanyan's situation into a concrete plot event. A useful checkpoint is the way the scene starts with This time at the alliance meeting, Wushuang and Hanqiong haven't... and follows through with They both realized something, and looking at Li Xuantiang at the....
Chapter 208, "Great Xia Sacred Pattern, Building Upgrades (Part 3)", is the clearest early answer because Xia Chuan finally turns buildup into a real advancement. The setup is The resources needed for the next upgrade of these buildings are not..., but the pressure keeps building through The problem is, Great Xia still doesn't know what a silver mine looks....
Chapter 226, "Beehive Incident, Lin Ye Is Dead", is the clearest early answer because the violence around Hive Station becomes final instead of hypothetical. It opens with The Hive Station is underground, with a total of twenty-seven... and closes on The main area still has over six hundred Earth-digging Realm and more.... The key payoff is that the chapter closes with Unfortunately, as soon as he poked out half his head, he felt a fierce blade flash, his neck slightly cool.