Lily Knight, who played Glory’s minion Gronx, has also appeared in The Singing Detective, Secretary and Artificial Intelligence: AI.

Wade Williams, who played General Gregor in Spiral, has also been in Erin Brockovich, MDs, 24, Enterprise, Six Feet Under, Charmed, The X Files, Becker, Star Trek: Voyager and The Larry Sanders Show.

Karim Prince, who played Dante, a Knight of Byzantium, in Spiral has also appeared in Malcolm in the Middle (as Cadet Stanley), The Bold and the Beautiful (as Raymond), MTV’s Undressed (as Randall), and Mighty Morphin’ Power Rangers (as Cestro/Blue Alien Power Ranger).

In her spell on Glory in Tough Love, Willow says, “Kali, Hera, Kronos, Tonic. Air like nectar, thick as onyx. Cassiel by your second star, hold my victim as in tar!” Kali is the Hindu goddess of destruction and death, Hera is the Queen of the Greek gods and wife …

In Tough Love, Giles says people keep trying to return petrified hamsters to the Magic Box. In Life Serial, Buffy discovers a jar of petrified hamsters in the basement of the magic shop.

Xander calls Buffy “Buffster” in the episodes Dead Man’s Party, Revelations, Buffy vs Dracula and Tough Love.

In Tough Love, Willow reminds Tara that she took Psych 101 from an evil government scientist (Professor Maggie Walsh) who was skewered by her Frankenstein-like creation (Adam, in The I in Team).

The massive amount of bruising seen on Spike’s face in Tough Love is from when Glory beat him up to try and get information on the Key in Intervention.

In Intervention, Buffy says, “Glory’s Key-sniffing snake was about here when I killed it. It was headed back to her.” This is a reference to the snake-demon Sobek in Shadow, which was raised by Glory to hunt out the Key. Buffy killed Sobek before it had a chance to return …

The desert in which the mountain lion leads Buffy on the vision quest in Intervention is the same desert which Buffy dreamed about in Restless. She says she remembers it. It’s also the first place she saw the First Slayer in Restless.

Xander says of Buffy and the Buffybot in Intervention, “They’re both Buffy”. This is a reference to his experience of his personality being split in two in The Replacement.

Giles uses a magic gourd in Primeval, and on the vision quest in Intervention.

Spike’s jealousy over his fellow vampire Angel is shown again in Intervention as he has asked Warren to programme the Buffybot to say, “Angel’s lame. His hair grows straight up and he’s bloody stupid.” This jealousy was first explored in season two when Angelus flirted with Spike’s girlfriend, Drusilla.

The First Slayer says to Buffy in Intervention, “Love. Give. Forgive”. This is a foreshadowing for upcoming events: Buffy loves Dawn and tries to protect her, she then gives her life for her and finally, Buffy forgives her friends for resurrecting her. The First Slayer also tells Buffy that death …

We learn in Intervention that Glory can’t brain-suck vampires.