Handing Over the Cheat Code to the Country

One day, Gu Yan discovered that every time he opened a door, he would time-travel. The time was random, the location was random, and even the era and environment he traveled to were unpredictable. The only certain thing was that the trigger was a door. In his past life, Gu Yan used this golden finger to amass great wealth. But after being reborn, the first thing he did was contact his biological family and offer his abilities to the nation. ... From the interstellar world, he brought back special energy sources, minerals, and high-tech advancements, accelerating technological progress. From the primitive world, he retrieved century-old medicinal herbs and countless oversized fruits, enriching the national treasury. From the ancient world, he reclaimed rare treasures, devised strategies to recover lost artifacts, and preserved forgotten craftsmanship. From the apocalyptic world, he obtained mysterious energy crystals, leading to the development of a cure for cancer. ... Watching Blue Country's rapid development, the entire interstellar world went crazy. Other nations demanded, "What’s going on with you?! Did you get help from aliens?" Blue Country’s leaders simply smiled. "No aliens here—just one exceptionally patriotic citizen." ...