That's a fantastic and evocative start to a story! It immediately grabs the reader with the unexpected. Here are a few ways we could develop this initial concept, along with some potential story hooks:

**Building on the Intrigue:**

*   **The Scientist:**
    *   **Focus on their reaction:** What's their name? Are they skeptical, awestruck, terrified, or a combination? Describe their first encounter in vivid detail. "Dr. Anya Sharma swallowed, her breath catching in her throat. The sunlight glinted off the horn of the largest unicorn, a creature of improbable beauty, silhouetted against the emerald green valley floor."
    *   **Their motivations:** Why were they exploring? What are they hoping to achieve by finding the unicorns? Are they driven by scientific curiosity, a personal obsession, or something more sinister?
    *   **Their challenges:** What obstacles do they face (terrain, the unicorns themselves, the elements, rivals)?
*   **The Valley:**
    *   **Descriptive details:** What makes the valley unique? Is it a hidden paradise, a harsh environment, or something in between? Describe the flora, fauna (besides unicorns!), and any unusual features. "The air thrummed with the buzz of unseen insects, and orchids the size of dinner plates dripped with morning dew. The valley's sides were lined with waterfalls that cascaded into crystalline pools, where the unicorns would drink..."
    *   **Secrets:** Does the valley have a secret history? Are there clues to a lost civilization or a forgotten magic? Does the valley have magical properties that sustain the unicorns and/or add another layer of potential conflict?
*   **The Unicorns:**
    *   **The herd:** Are they gentle and peaceful? Are they wary of humans? Are they magical? Do they have a leader? What do they eat, how do they communicate?
    *   **Their story:** Why are they in this remote valley? Are they the last of their kind? Is there a reason why they are hiding?
    *   **Their vulnerability:** Could their existence be threatened by the scientist, a corporation, or any outside entity.

**Potential Story Hooks/Directions:**

*   **The Protect and Save:** The scientist vows to protect the unicorns from the outside world. This could involve hiding the valley, fighting poachers, or raising awareness.
*   **The Scientific Discovery:** The scientist wants to study the unicorns, leading to ethical dilemmas about interfering with their lives. They might be trying to determine the genetic makeup of the unicorns, discovering a cure for a disease, or seeking other scientific advancements.
*   **The Exploitation:** A corporation learns about the discovery and wants to exploit the unicorns for their horns (believed to have magical properties), their blood, or other resources. The scientist must fight to protect the herd.
*   **Internal Conflicts:** The scientist may have to decide whether to share their findings with the world or keep it secret. Other scientists could try to steal all of their findings from them.
*   **Magical Adventure:** If the unicorns are magical, perhaps the valley is a portal to another realm, or the unicorns themselves are linked to ancient prophecies.
*   **Cultural Clash:** If the scientist comes from a place where unicorns are mythical, they would need to adapt to the reality of the creatures themselves.

**Possible Opening Sentences (Building on yours):**

*   "In a shocking finding, scientist Dr. Anya Sharma stumbled upon a herd of unicorns living in a remote, previously unexplored valley, nestled deep within the Andes Mountains - a discovery that both thrilled and terrified her."
*   "The air grew thick with the scent of wild jasmine as a group of scientists ventured into a previously uncharted valley in the Andes. They had heard rumours of strange lights but never were they ready for what they found - a herd of majestic unicorns grazing peacefully in a meadow."
*   "The first sign something extraordinary was about to happen was an unnatural rainbow of color that danced across the sky. Then, they saw them. In the previously unexplored Andes, a scientist discovered the impossible: unicorns."

No matter what direction you take it, your initial premise is engaging! Have a great time writing!
