All Souls' Day...

I'm probably betraying quite a narrow cultural horizon, but in my opinion the two greatest poetic works dealing with the subject of the souls in purgatory are Dante's Purgatorio and Newman's Dream of Gerontius. Objectively speaking, I suppose that Dante's is the greater work, though comparing them is like trying to compare the Summa to the Story of a Soul - each genius is of a different kind.
However, I do think that the sheer scale and scope of Dante's work means than Newman's theological insight is keener and much more concise. One doesn't have to wade through scores of inventive punishments or obscure historical figures. Focusing on the journey of the single soul, Newman imagines the condition of the soul immediately after judgement - he is safe, but is unable to endure the Divine Love without purification:

Take me away, and in the lowest deep
There let me be,
And there in hope the lone night-watches keep,
Told out for me.
There, motionless and happy in my pain,
Lone, not forlorn,—
There will I sing my sad perpetual strain,
Until the morn.
There will I sing, and soothe my stricken breast,
Which ne'er can cease
To throb, and pine, and languish, till possest
Of its Sole Peace.
There will I sing my absent Lord and Love:—
Take me away,
That sooner I may rise, and go above,
And see Him in the truth of everlasting day.

The soul yearns for purgation!
Within the 'golden prison' the souls sing the 90th Psalm and there can be few more touching sentiments than those expressed by the Guardian Angel as he escorts his charge to the place of purification:

Softly and gently, dearly-ransom'd soul,
In my most loving arms I now enfold thee,
And, o'er the penal waters, as they roll,
I poise thee, and I lower thee, and hold thee.

And carefully I dip thee in the lake,
And thou, without a sob or a resistance,
Dost through the flood thy rapid passage take,
Sinking deep, deeper, into the dim distance.

Angels, to whom the willing task is given,
Shall tend, and nurse, and lull thee, as thou
liest;
And masses on the earth, and prayers in heaven,
Shall aid thee at the Throne of the Most
Highest.

Farewell, but not for ever! brother dear,
Be brave and patient on thy bed of sorrow;
Swiftly shall pass thy night of trial here,
And I will come and wake thee on the morrow.

I have sometimes reflected what a delicious agony the pains of purgatory must be - painful indeed to be seperated from the Lord, yet with the sure and certain hope of seeing Him face to face. These are suffering souls, but blessed souls too. I wonder if purgatory resembles the pain endured by the genuine mystic who strongly experiences the Divine Love but knows that the ecstacy experienced is not even a fraction of the joy of the Beatific Vision.
How marvelous, too, it is that by our prayers we can help them in their purification. May the Holy Souls be a reminder to us of the bonds of charity and grace that bind us together into the one Body of Christ.