Detective Field Guides • Official Series HQ

Turn Every Walk Outside Into a Field Investigation

Explore three illustrated outdoor mystery field guides—Backyard Detective, Pavement & Park Detective, and Woodland & Trail Detective—paired with the 100% offline Detective Companion App for Android.

Explore the 3 Field Guides Discover the Companion App
3 Books Backyard, Urban & Woodland
120 Missions 40 Field Cases Per Book
18+ Badges Ranks & Field Credentials
100% Offline Zero Ads, Zero Tracking
The Book Trilogy

Three Field Guides. 120 Outdoor Science Mysteries.

Each book in the series contains 40 hands-on nature investigations organized into five themed field divisions. Read the case briefing in your book, step outside to gather real-world evidence, and log your discoveries in the companion app.

Book 1 • Home & Garden

Backyard Detective

40 Backyard Science Missions

Uncover the hidden wildlife headquarters right outside your back door! Flip rotting logs to inspect armored isopods, test earthworm vibrations, decode leaf vein blueprints, track busy pollinators, and read clouds like a field meteorologist.

5 Field Divisions (8 Missions Each):
  • 🪨 Soil & Underground
  • 🌿 Plant Anatomy & Trees
  • 🐝 Bugs, Pollinators & Critters
  • ☁️ Weather, Sky & Observation
  • 🦉 Habitats & Sensory Ecology
Featured Cases: Micro-City Siege (The Log Flip Investigation), Worm Race & Rescue, Leaf Vein Blueprints, and 37 more backyard mysteries.
Book 2 • Sidewalks & City Parks

Pavement & Park Detective

40 Urban Nature Missions

No backyard? No problem! Discover how tough pioneer plants, mosses, lichens, insects, and urban birds conquer concrete, brick walls, street trees, and neighborhood parks right in the heart of the city.

5 Field Divisions (8 Missions Each):
  • 🌱 Concrete Crack Pioneers
  • 🧱 Brick, Stone & Metal Micro-Habitats
  • 🌳 Street Trees & Park Canopies
  • 🐦 City Survivors & Alley Wildlife
  • 🏞️ The Municipal Park Safari
Featured Cases: The Sidewalk Fracture (Broadleaf Plantain & Root Anchors), Tar-Seam Moss, Wall Lichen Maps, and 37 more urban nature cases.
Book 3 • Forests & Nature Trails

Woodland & Trail Detective

40 Forest Expedition Missions

Venture onto shady woodland footpaths to investigate deep leaf litter, fallen nurse logs sprouting new seedlings, towering canopy architecture, pinecone weather gauges, secret animal tracks, and forest micro-climates.

5 Field Divisions (8 Missions Each):
  • 🍂 The Forest Floor & Deep Leaf Litter
  • 🌲 Giants of the Canopy & Trunk Architecture
  • 🌰 Conifers, Cones & Seed Travelers
  • 🐾 Woodland Critters, Birds & Secret Tracks
  • 🧭 Forest Micro-Climates & Sensory Trail Craft
Featured Cases: The Leaf Litter Blanket (Duff & Humus), Rotten Log Hotel & Nurse Logs, Pinecone Hygrometers, and 37 more trail expeditions.
Official Android Companion

Inside the Detective Companion App

Designed as a pocket-sized Digital Field Headquarters, the Detective Companion App pairs seamlessly with all three books—or works on its own—so young investigators can decode clues, sketch specimens, and track their detective career anywhere outdoors.

120 Briefings & Word Clue Hunts

Every mission from all three books includes an illustrated field briefing, an outdoor safety rule, interactive masked-word science clues to decode, and one-tap offline Read-Aloud (Text-to-Speech).

Specimen Sketch Pad & Field Log

Check off real-world field evidence, log weather and soil conditions, write your final detective verdict, and draw your specimen using multi-brush tools and nature guide templates (magnifier, grid, ruler, and cross-section).

Guided 10-Minute Field Timer

Short on time? Launch the structured 10-Minute Outdoor Investigation timer on the home dashboard, breaking any walk into three focused phases: Quiet Observation, Clue Collection, and Field Sketching.

Symmetry Lab & Cloud/Track Quiz

Practice biological bilateral symmetry in the interactive Nature Symmetry Lab and test your wildlife tracking and meteorology skills in the Cloud & Animal Track Identification Quiz.

Biodiversity Bingo & 4-Season Quests

Spot 16 illustrated backyard and park wonders on the Biodiversity Bingo board, tally sightings in the Master Species Census, and complete year-round 4-Season Nature Quests.

Investigator Credentials & Badges

Customize your Investigator ID card, take the 5-rule Official Field Code Pledge for gentle nature stewardship, unlock 18+ specialized achievement badges, and climb from Rookie Observer to Chief Nature Detective.

Step 1

Pick Your Book & Case

Choose from Backyard, Pavement & Park, or Woodland & Trail and read or listen to the mission briefing.

Step 2

Decode the Science Clues

Solve the 3 interactive scientific vocabulary clues to unlock the Field Evidence Checklist.

Step 3

Head Outdoors & Observe

Follow the ethical safety rule, complete your real-world observation checklist, and record your detective verdict.

Step 4

Sketch & Earn Your Badge

Draw your discovery on the Specimen Sketch Pad to stamp the case solved and advance your Investigator Rank!

🛡️ Built for Families & Classrooms: 100% Offline & Private

Detective Companion App (com.detectivecompanion.app) is engineered with strict privacy by design. The app works completely offline in backyards, parks, and forest trails without internet access and requests zero Android device permissions.

✓ Zero Personal Data Collected ✓ No GPS or Location Tracking ✓ No Ads or In-App Purchases ✓ COPPA & Google Play Families Compliant
Read Full Privacy Policy →

Questions, Feedback, or Educator Inquiries?

Need support with the Detective Companion App or have a question about the Backyard Detective, Pavement & Park Detective, or Woodland & Trail Detective books at detectivefieldguides.com? Reach out directly to the developer: