Possible Clues:

• Pagan divinity of moon manifest round end of April
• Spiny lizard from Missouri heading for Scottish waters
• The doctor needed a fire over the Scottish water
• The doctor might have had one burning over the water in Scotland
• This 33 down gets the doctor to the water in Scotland (6)
• Doctor the water to find a lizard
• 4 to skulk around lake
• Semitic god taking very little time to reach lake
• The fiery, idle-sounding, doctor gets over the lake in Scotland
• The heathen medical god over the water of Scotland