Two detectives join forces to find a serial killer with a personal agenda.
Use one of the services below to sign in to PBS:
tried to add this video to your Watchlist so you can watch
it later. But first, we need you to sign-in to PBS using one
of the services below. You’ll be able to manage
videos in your Watchlist, keep track of your favorite shows,
watch PBS in high definition, and much more!
tried to select this program as one of your favorites. But
first, we need you to sign-in to PBS using one of the
services below. You’ll be able to manage videos in
your Watchlist, keep track of your favorite shows, watch PBS
in high definition, and much more!
To get you
watching PBS in high definition we need you to sign-in to
PBS using one of the services below. You'll be able
to manage videos in your Watchlist, keep track of your
favorite shows, watch PBS in high definition, and much more!
Don’t have a PBS Account? Create one nowCreate a PBS account
Providing Support for PBS.org
Learn More about PBS online sponsorship
Why More Testing Is Good
Students who get tested a lot without being graded can more easily recall what they learn.
Add to Watchlist
Share this video:
Share this video on FacebookShare this video on Twitter
Where Your Face Comes From
When you were an embryo, a parade of molecules sculpted the cells that became your face.
The Hole in the Sky
That time when NOVA reported on the first sign of the ozone hole's depletion...in 1986
The Serengeti Lion Project
After 50 years, Craig Packer & his team have records of the nearly 5,000 Serengeti lions.
NOVA Black Holes App
In this iPad app, navigate fields of cosmic objects in your quest to become a black hole.
Make Your Own Hydrothermal Vent
A step-by-step guide to create your very own hydrothermal vent
3 Things "Faster Than Light"
These three things have been said to go faster than light, but do they?
The Physics Behind Texting
When you send a text, how does your message make the journey to your friend’s phone?
Saving the Montauk Lighthouse
A unique method to fight erosion saved the Montauk Point Lighthouse from disaster.
Gravity Changes Colors
This ingenious experiment proves that gravity changes the color of light all around us.
Alzheimer's Clinical Trials
Real patients and families describe what it's like being in an Alzheimer's clinical trial.
Alzheimer's Other Victims
Family members describe what it's like to have a loved one with Alzheimer's.
Alzheimer's Virus-Like Protein
Tangles of a protein called tau inside neurons may be the culprit behind Alzheimer’s.
Inside the Mind of Alzheimer’s
Journalist Greg O'Brien gives a first-hand account of what it's like have Alzheimer's.
Certain gene forms increase your risk of developing Alzheimer's.
David Lynch x Robots = A.I. Art
David Lynch puts a literal face on the oddest collection of little learning robots.
Ötzi the Iceman's Ax
How did Ötzi the Iceman, who lived 5300 years ago, sharpen his ax?
Implanting False Memories
How to make someone believe they’ve committed a crime that never happened.
Amazing Calendar Trick
With a dash of math, know the day of the week for any date on the calendar.
The Hidden Fluorescent World
The proteins that make fish fluoresce could help scientists map the human brain.
How to Find a Galaxy
Knowing the addresses of a thousand galaxies yielded a remarkable picture of our universe.
A Rock Symphony
Robert Hazen is a geologist who plays music—two interests that have a lot in common.
It’s possible to find all of Earth’s history tucked inside a market stall in Morocco.
Support for PBS.org provided by: