The new threat

BBC Security Correspondent Frank Gardner investigates the nature of the new terrorist threat and why Britain has become a prime target for Al Qaeda.

He examines how the intelligence services assess possible threats and how confident they are in distinguishing the real dangers from the hoaxes.

The targets

Sally Magnusson asks a panel of experts, including former terrorists, to assess the possible targets of attack.

The group discusses potential methods from aeroplane hijacks to dirty bombs and suicide attacks.

They also review the security measures in place to prevent successful attacks.

The reactions

Vanessa Collingridge questions how prepared Britain would be if it faced a chemical, biological or nuclear attack in a public place.

She asks if we have the resources, equipment and planning to cope.

The human cost

John Sweeney examines the new legislation that allows the government in a "state of emergency" to bypass the Human Rights Act and detain foreign terrorist suspects indefinitely.

He talks to the families of those detained in Britain and in Guantanamo Bay in Cuba and questions whether, in the name of security, the government is in danger of undermining fundamental human rights.