Roots: The Doctor appropriates Julius Caesar Act I (ii) ("Mr Kreevy has a lean and hungry look") Markus and Ace discuss James Bond and The Saint and later he compares her to Beryl the Peril of Topper comic. Ace remarks of Hhessh "his phaser's set to stun" (Star Trek) The Italian Job (including the line "you were only meant to blow the bloomin' doors off!"). The Adjudicator calls the Doctor Raine's "Fairy Godfather". Markus refers to "the Twins" - presumably the Kray Brothers; his mother is Mention is made of Sandi Shaw's Puppet on a String and Engelbert Humperdink's The Last Waltz. The Doctor says that Sleeping Beauty is one of his favourite stories

Goofs: Hhessh says he is looking for Sezhyr's lost "reliquary", which ought to describe a receptacle for relics, not a collection of them.

Fluffs: The Orb of Alikyr sounds instead rather like it was made at Ikea.

Dialogue Triumphs: "Bones grow flesh, hope waters the dust. Lost legions march home."

"There was war - the old beliefs were cast down, the storms of revolution filled the skies"

"Honour and glory, glory and honour"

Continuity: Ice Lords respect displays of strength. The Doctor says of the Martian race "we have a chequered history".

The Martians here have an interplanetary shuttle which (due to its low power) is only capable of orbital trips. It has vertical take-off capability and (presumably) some form of cloaking device. These Ice Warriors have been stranded on Earth for 43 years, and only seven 'old Warriors' remain (Hhessh later says there has been no transmission from mars received for forty years). Among them, Hhessh is reluctant to return to the Red planet - or is at least reluctant to return Sezhyr there; Glarva is seemingly at peace with returning home once the Warriors are able. The Doctor remarks that Mars is "half abandoned, half-asleep". He remarks that the bikers' helmets recall "a certain warlike implacability characteristic of the Third Polar Epoch. Hhessh is unaware of the term Time Lord, but knows enough of human physiology to call Ace a "child". Ice Warriors of the polar regions subsist on a diet of glacier fish, found in the region's solid ice.

The Martian Relics of Nobles include a helmet, gauntlets, chest plate, jewelled sword, orb and power cells for a spaceship. A Martian sonic grenade resembles a green Faberge egg, but with distinctively different appliqués (actually diamond circuitry). It works by sonic impulse causing a violent implosion of the eardrums of anyone in range. All were recovered from a crashed shuttle recovered from the Baring Sea two years previously, by a Russian sub - the Soviet Union has attempted to reverse-engineer the armour for use by their troops, and with some limited success. Ice Marshall's helmet contains circuitry below its surface which acts as an extra nervous system, bonding with the cranium of its wearer (we might infer that Sezhyr's helmet rejected the human soldiers 'volunteered' for the experiment due to their having been deserters?) In all an Ice Warrior's exoskeleton armour melds with the wearer's body - Hhessh remarks that they are "one with their armour". Sezhyr's helmet, in combination with his self-designed essence-container the Orb of Alikyr, acts with a degree of autonomy, seeking out a potential wearer and 'reprogramming' human physiology into something resembling that of a Martian, replacing the host's consciousness with that of Sezhyr while remaining implacably on the host's head. Martian armour technology includes locked-sequence communicators and induced-muscular hydraulics, both of which the Soviet army have converted for their use.

Sezhyr was first Marshall of the Ice Army. With his jeweled sword he slew the leader of the Dust Rebellion. He is regarded as the greatest war-wright and strategist of his race, a visionary who united the armies of Mars, but also a tyrant who put many of his dissenters to the gun. He talks to Hhessh of "riding out" to battle (were there Martian cavalry?). During a period of Mar's planetary peril Sezhyr founded the Ice Army and defended the city of Jurbizz against the rebel Dust Riders (his jewelled sword was stolen from the leader of the Dust Rebellion), and fought with the kings of the Blood Gullies, his banner flying over a hundred cities on the planet and its moons Hhesh was born into his service, but fled the planet after the Marshall's death a thousand years ago. The Ice Army was split and fractioned with only Hhessh's troops remaining - many of Sezhyr's followers were chained to the planet's surface to face the Red Dawn

Lt Raina Kerenskaya is from Kiev and had a grandfather who was a fur-trapper in the Ukraine. At the time of this story she is pregnant at fifteen weeks gestation.

Markus Creevy has a 2-up, 2-down in Bethnell Green which he shares with his mother.

Eight ounces of Nitro-9 will suffice to blow a hole in a three-inch tungsten door (it proves more than enough in the end). Ace sees Uri Gagarin and Valentina Tereshkova during the October parade. He mother moves into her present home five years after the current story (circa 1972). Adjudicator of the Prydon Academy. Ace would have been the only human to attend, had she been successful as an applicant. For his own part, the Doctor thought Prydon Academy was "awful."

This is Ace's first encounter with an Ice Warrior.

The Doctor seems to know Raina will have a girl, but appears to be surprised by the name Raine (or he at least does a good job of appearing surprised) - the Adjudicator's remarks certainly hint that the Time Lord is aware in some part of the role he will play in the child's life. The Doctor says he hasn't 'exactly' delivered a baby before (though he will later in The Settling). He tells Ace he liked her calling him "professor." To Markus he says "you should have seen where I came from!"

Links: "Come along, Professor, we've still got work to do." 45: 1945 (Ace's mother's address) Red Dawn. Ace's outburst about the Doctor recalls "Perivale, Fenric and all that" (Ghost Light, The Curse of Fenric).

Untelevised Adventures: The Doctor says he was last in the Kremlin "feels like centuries ago" (this may be the same recollection of events shared by the Doctor in Singularity.)

Location: Moscow and London's East End, November 1967.

The Bottom Line: "Most secrets lose their lustre once they are revealed."

The past is never how you imagined it to be, and perhaps this is the case for Thin Ice (nee Ice Time for many fans) Still, Ice warriors driving Bentleys, eating fish fingers and fretting over the next day's papers and news media is worth the jarring contradictions to 'informed knowledge' about Ace's supposed destiny. If this start is anything to go by, the 'recovered' Season 27 could be a lot more surprising than initially thought.