A1-01 Aerospace Engineer Cheng Xin

Late 2010s, Beijing.

Your name is Cheng Xin. You are twenty-eight years old, a young engineer in China's aerospace program. You've dreamed of the stars since childhood — not in the literary, romantic sense, but in terms of real, physical interstellar exploration. Your specialty is aerospace propulsion systems; you know the combustion chamber flow fields of rocket engines like the back of your hand.

But today, you are sitting in a conference room of the Planetary Defense Council (PDC), facing something far beyond any routine project.

Since the Trisolaran Crisis became public, the entire world has been reorganizing in panic. The Trisolaran Fleet is heading toward Earth at one percent the speed of light, estimated to arrive in four hundred years. Four hundred years — it sounds distant, but for a civilization that needs to bridge a vast technological gap, time is not abundant.

The Wallfacer Project has already been launched. Four Wallfacers have been granted unquestioned authority, each devising their own secret strategies. But beyond the Wallfacer Project, humanity needs more ways to understand the enemy.

You were summoned here because you proposed a bold idea.

Your plan is called the "Staircase Project" — using a series of nuclear detonations to accelerate an extremely light probe, sending it toward the Trisolaran Fleet. If everything goes well, this probe could catch up with the fleet's vanguard within decades, gathering intelligence at close range.

The problem is: with existing technology, the probe's payload capacity is extremely limited. You've calculated that the entire probe (including the acceleration sail) cannot weigh more than a few dozen kilograms. This means —

"You can't possibly send a complete probe," the meeting chair says. "What can you fit in that weight? A camera?"

You take a deep breath. You know the answer, but saying it aloud takes courage.

Your calculations show that the weight is... just enough to send a human brain.

If a person's brain were extracted, frozen, and wrapped in radiation shielding, it could serve as the Staircase Project's "probe" and be sent into the Trisolaran Fleet. Trisolaran technology far exceeds humanity's — if they are willing, they might be able to revive the brain, or even reconstruct a body for it. This would be humanity's ultimate spy, sent directly into the enemy's ranks.

Of course, the premise of this idea is: you need to find a person, extract their brain, and launch it into space.

The conference room falls silent.

You have your plan, but saying "send a person's brain" is something that requires you to cross a threshold in your heart.

You look around the conference room — military representatives, scientific advisors, PDC officials — everyone is waiting for you to speak.