This is a short English version of an old Scottish ballad--many versions go into much more detail. This one is based on the singing of Ben Butcher (excellent name for a ballad singer!) in 1955. What is going on here? A family feud on steroids enhanced by various intrigues. Notice, for example, that Betsy is Lincoln's "blood's flower."In most versions, Lamkin/Lincoln slays the lord's son and wife in a gruesome fashion, but not Betsy.  When the lord gets home, Betsy says "Don't blame me--it was the nurse and Lincoln who did it." In most versions, the nurse ("false nurse") lets Lamkin/Lincoln in and encourages him to murder the lady of the house on the grounds that she has mistreated the nurse.

How did Lincoln get into the house? In some versions he is a mason who helped build the house (or "castle"). He knows the house well, including a place where he can slip inside. In any case, the nurse assists his entry, and she or he pinches the baby to get the attention of the lady of the house.

The lady of the house does not come out looking very good even though she is the victim. In some verses she encourages Lincoln to be satisfied with killing her baby and thus spare the lady. In some cases, she offers him money:

O spare my life Rankin, Oh save it most sweet
I'll  give you as monie [many] guineas as there's stanes in the street

Rankin/Lincoln is a man of principles, however. He is not interested in money, only justice. In some versions he sarcastically retorts that with all the lady's money, he will buy her a fancy coffin. Tension between aristocracy vs. commoners or rich vs. poor runs through many versions. For example, in one, Lamkin asks the nurse to hold the basin to catch the lady's blood. The nurse replies:

There need nae bason, Lamkin; lat it run through the floor
What better is the heart's blood o the rich than o the poor?

Indeed, this whole idea of catching the lady's blood in a basin is because her blood is noble and thus somehow deserving of special treatment. Not that her noble status helps much. In one version, Blankin performs the following deed:

Then he cut off her head fram her lily breast-bane
And he hung it up in the kitchen, it made the ha shine

And, of course, there wouldn't be closure without an account of the cruel and unusual retribution the lord metes out to Lincoln and the nurse. In one version:

The false nurse was burnt on the mountain hill-head
And Rankin was boiled in a pot full of lead

This is the classic old ballad: nearly everyone dies, the survivors are miserable, and there is cruelty, class-based tension, revenge, treachery  . . . and all the other stuff of popular tabloids.

In Appalachia there was a tendency to claim that these ballads serve a moral purpose, typically a warning of some sort. But their popularity was surely the result of their entertainment value. Look at what is popular on TV today, ca. 2008. Torture porn, for example, is now both mainstream and patriotic (do you enjoy watching 24 or its many imitators?). People haven't changed all that much.

Notice that some lines don't rhyme or are short of words. They probably did once rhyme in an earlier Scots version, but time has changed the song.