Can your students solve the mystery of Hollow Creek Lab using scientific evidence? In this Halloween science mystery, students investigate strange events at an abandoned-looking school laboratory. A specimen collection has disappeared, footprints cross the floor, a warning appears on the board, the temperature drops, and scratching is heard inside a wall. Rumors aren’t evidence. Students examine five evidence files, compare explanations, eliminate unsupported suspects, and write a final Claim-Evidence-Reasoning (CER) explanation of what happened. Designed for middle school science, Grades 6–8 (approximately ages 11–14), this activity gives students practice with scientific reasoning through a seasonal mystery. Use it for a Halloween lesson, science-skills review, enrichment, or a lesson before break. Students will Distinguish observations from inferences Compare measurements and interpret data tables Analyze simulated chromatography results Create and interpret a line graph Identify independent and dependent variables Calculate temperature change and identify patterns Interpret suspect timelines and airflow data Evaluate evidence, revise hypotheses, and eliminate unsupported explanations Write a CER explanation using evidence from at least three files What’s included 21 pages total: 1-page teacher guide 12-page student investigation 7-page complete teacher answer key Thank-you and terms-of-use page Inside the student investigation Case File #1031: The Haunting of Hollow Creek Lab Suspect Files: Review four suspects and record an initial hypothesis Investigator’s Evidence Log: Track observations and possible explanations Evidence File 1 — The Footprints: Compare shoe measurements and tread patterns Evidence File 2 — The Message: Use chromatography results to compare mystery ink Evidence File 3 — Temperature Data: Graph temperatures, calculate change, and identify variables Evidence File 4 — Suspect Timeline: Compare photographs, camera records, key-card records, and suspect locations Evidence File 5 — The Scratching in the Wall: Analyze airflow data Evidence Board: Weigh evidence for and against each suspect Final Case Report: Write a CER explanation using at least three evidence files Case Closed Reveal and Science Reflection

Teach a connected middle school Earth science sequence on weather and the atmosphere, from the Suns energy and uneven heating to air masses, fronts, thunderstorms, and severe weather. This two-unit bundle includes approximately 17 to 20 class periods of instruction, or about 3–4 weeks, depending on your schedule. Students build understanding through science readings, data analysis, hands-on investigations, graphing, weather-map interpretation, CER writing, assessments, and an engineering challenge. Unit 1: Weather Foundations Students explore weather variables and instruments, solar energy, energy transfer, uneven heating, convection, density, air pressure, wind, and local winds. Includes: Teacher pacing and planning guide for 11–12 class periods Guided notes and teacher answer key Reading and comprehension activity Weather instruments and data-analysis activity Two-day land-versus-water heating investigation, with student materials, answer key, and teacher guide “What Powers Weather?” CER writing activity 100-point unit quiz and answer key Unit 2: Air Masses, Fronts & Storms Students classify air masses, examine how fronts form, interpret weather maps and pressure systems, and investigate cloud formation, precipitation, thunderstorms, tornadoes, supercells, and wind shear. Includes: Teacher pacing and planning guide Presentation Guided notes and complete teacher answer key “When Air Masses Collide” reading and comprehension activity Weather Balloon Parachute Challenge, with repeated trials, averages, graphing, analysis, and redesign “Can Fronts Create Storms?” CER writing activity Vocabulary reference sheet Unit quiz and answer key Skills students practice Students interpret scientific texts, tables, graphs, weather data, and maps; identify variables; conduct investigations; calculate averages and temperature changes; make evidence-based forecasts; write CER explanations; and design, test, evaluate, and improve an engineering solution.